Редактирование: Qt:Документация 4.3.2/qstring

{{Qt4.3.2_header}}

=QString Class Reference<br /><sup><sup>[модуль [[Qt:Документация 4.3.2/qtcore | QtCore]] ] </sup></sup>=

The QString class provides a Unicode character string. [[#details | More...]]
<source lang="cpp-qt"> #include <QString></source> 
Inherited by [[Qt:Документация 4.3.2/qconststring | QConstString]], [[Qt:Документация 4.3.2/qdbusobjectpath | QDBusObjectPath]], and [[Qt:Документация 4.3.2/qdbussignature | QDBusSignature]].

'''Note:''' All the functions in this class are [[Qt:Документация 4.3.2/threads#reentrant | reentrant]], except [[Qt:Документация 4.3.2/qstring-qt3#ascii | ascii]](), [[Qt:Документация 4.3.2/qstring-qt3#latin1 | latin1]](), [[Qt:Документация 4.3.2/qstring-qt3#utf8 | utf8]](), and [[Qt:Документация 4.3.2/qstring-qt3#local8Bit | local8Bit]]().

*[[Qt:Документация 4.3.2/qstring-members | Список всех членов включая унаследованные]]
*[[Qt:Документация 4.3.2/qstring-qt3 | Поддержка членов Qt 3]]
<div id="public-types"></div>
===Открытые типы===

*class '''[[Qt:Документация 4.3.2/qstring-null | Null]]'''
*enum '''[[Qt:Документация 4.3.2/qstring#NormalizationForm-enum | NormalizationForm]]''' { NormalizationForm_D, NormalizationForm_C, NormalizationForm_KD, NormalizationForm_KC }
*enum '''[[Qt:Документация 4.3.2/qstring#SectionFlag-enum | SectionFlag]]''' { SectionDefault, SectionSkipEmpty, SectionIncludeLeadingSep, SectionIncludeTrailingSep, SectionCaseInsensitiveSeps }
*flags '''[[Qt:Документация 4.3.2/qstring#SectionFlag-enum | SectionFlags]]'''
*enum '''[[Qt:Документация 4.3.2/qstring#SplitBehavior-enum | SplitBehavior]]''' { KeepEmptyParts, SkipEmptyParts }
<div id="public-functions"></div>
===Открытые функции===

*'''[[Qt:Документация 4.3.2/qstring#QString | QString]]''' ()
*'''[[Qt:Документация 4.3.2/qstring#QString-2 | QString]]''' ( const QChar * ''unicode'', int ''size'' )
*'''[[Qt:Документация 4.3.2/qstring#QString-3 | QString]]''' ( QChar ''ch'' )
*'''[[Qt:Документация 4.3.2/qstring#QString-4 | QString]]''' ( int ''size'', QChar ''ch'' )
*'''[[Qt:Документация 4.3.2/qstring#QString-5 | QString]]''' ( const QLatin1String &amp; ''str'' )
*'''[[Qt:Документация 4.3.2/qstring#QString-6 | QString]]''' ( const QString &amp; ''other'' )
*'''[[Qt:Документация 4.3.2/qstring#QString-7 | QString]]''' ( const char * ''str'' )
*'''[[Qt:Документация 4.3.2/qstring#QString-8 | QString]]''' ( const QByteArray &amp; ''ba'' )
*'''[[Qt:Документация 4.3.2/qstring#dtor.QString | ~QString]]''' ()
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#append | append]]''' ( const QString &amp; ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#append-2 | append]]''' ( const QLatin1String &amp; ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#append-3 | append]]''' ( const QByteArray &amp; ''ba'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#append-4 | append]]''' ( const char * ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#append-5 | append]]''' ( QChar ''ch'' )
*QString '''[[Qt:Документация 4.3.2/qstring#arg | arg]]''' ( const QString &amp; ''a'', int ''fieldWidth'' = 0, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-2 | arg]]''' ( const QString &amp; ''a1'', const QString &amp; ''a2'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-3 | arg]]''' ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-4 | arg]]''' ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-5 | arg]]''' ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'', const QString &amp; ''a5'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-6 | arg]]''' ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'', const QString &amp; ''a5'', const QString &amp; ''a6'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-7 | arg]]''' ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'', const QString &amp; ''a5'', const QString &amp; ''a6'', const QString &amp; ''a7'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-8 | arg]]''' ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'', const QString &amp; ''a5'', const QString &amp; ''a6'', const QString &amp; ''a7'', const QString &amp; ''a8'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-9 | arg]]''' ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'', const QString &amp; ''a5'', const QString &amp; ''a6'', const QString &amp; ''a7'', const QString &amp; ''a8'', const QString &amp; ''a9'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-10 | arg]]''' ( int ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-11 | arg]]''' ( uint ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-12 | arg]]''' ( long ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-13 | arg]]''' ( ulong ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-14 | arg]]''' ( qlonglong ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-15 | arg]]''' ( qulonglong ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-16 | arg]]''' ( short ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-17 | arg]]''' ( ushort ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-18 | arg]]''' ( QChar ''a'', int ''fieldWidth'' = 0, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-19 | arg]]''' ( char ''a'', int ''fieldWidth'' = 0, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*QString '''[[Qt:Документация 4.3.2/qstring#arg-20 | arg]]''' ( double ''a'', int ''fieldWidth'' = 0, char ''format'' = 'g', int ''precision'' = -1, const QChar &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const
*const QChar '''[[Qt:Документация 4.3.2/qstring#at | at]]''' ( int ''position'' ) const
*int '''[[Qt:Документация 4.3.2/qstring#capacity | capacity]]''' () const
*void '''[[Qt:Документация 4.3.2/qstring#chop | chop]]''' ( int ''n'' )
*void '''[[Qt:Документация 4.3.2/qstring#clear | clear]]''' ()
*int '''[[Qt:Документация 4.3.2/qstring#compare-5 | compare]]''' ( const QString &amp; ''other'' ) const
*int '''[[Qt:Документация 4.3.2/qstring#compare-6 | compare]]''' ( const QString &amp; ''other'', Qt::CaseSensitivity ''cs'' ) const
*int '''[[Qt:Документация 4.3.2/qstring#compare-7 | compare]]''' ( const QLatin1String &amp; ''other'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*const QChar * '''[[Qt:Документация 4.3.2/qstring#constData | constData]]''' () const
*bool '''[[Qt:Документация 4.3.2/qstring#contains | contains]]''' ( const QString &amp; ''str'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*bool '''[[Qt:Документация 4.3.2/qstring#contains-4 | contains]]''' ( QChar ''ch'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*bool '''[[Qt:Документация 4.3.2/qstring#contains-5 | contains]]''' ( const QRegExp &amp; ''rx'' ) const
*int '''[[Qt:Документация 4.3.2/qstring#count | count]]''' ( const QString &amp; ''str'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*int '''[[Qt:Документация 4.3.2/qstring#count-2 | count]]''' ( QChar ''ch'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*int '''[[Qt:Документация 4.3.2/qstring#count-3 | count]]''' ( const QRegExp &amp; ''rx'' ) const
*int '''[[Qt:Документация 4.3.2/qstring#count-4 | count]]''' () const
*QChar * '''[[Qt:Документация 4.3.2/qstring#data | data]]''' ()
*const QChar * '''[[Qt:Документация 4.3.2/qstring#data-2 | data]]''' () const
*bool '''[[Qt:Документация 4.3.2/qstring#endsWith | endsWith]]''' ( const QString &amp; ''s'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*bool '''[[Qt:Документация 4.3.2/qstring#endsWith-3 | endsWith]]''' ( const QLatin1String &amp; ''s'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*bool '''[[Qt:Документация 4.3.2/qstring#endsWith-4 | endsWith]]''' ( const QChar &amp; ''c'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#fill | fill]]''' ( QChar ''ch'', int ''size'' = -1 )
*int '''[[Qt:Документация 4.3.2/qstring#indexOf | indexOf]]''' ( const QString &amp; ''str'', int ''from'' = 0, Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*int '''[[Qt:Документация 4.3.2/qstring#indexOf-2 | indexOf]]''' ( QChar ''ch'', int ''from'' = 0, Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*int '''[[Qt:Документация 4.3.2/qstring#indexOf-3 | indexOf]]''' ( const QRegExp &amp; ''rx'', int ''from'' = 0 ) const
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#insert | insert]]''' ( int ''position'', const QString &amp; ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#insert-2 | insert]]''' ( int ''position'', const QLatin1String &amp; ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#insert-3 | insert]]''' ( int ''position'', const QChar * ''unicode'', int ''size'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#insert-4 | insert]]''' ( int ''position'', QChar ''ch'' )
*bool '''[[Qt:Документация 4.3.2/qstring#isEmpty | isEmpty]]''' () const
*bool '''[[Qt:Документация 4.3.2/qstring#isNull | isNull]]''' () const
*int '''[[Qt:Документация 4.3.2/qstring#lastIndexOf | lastIndexOf]]''' ( const QString &amp; ''str'', int ''from'' = -1, Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*int '''[[Qt:Документация 4.3.2/qstring#lastIndexOf-2 | lastIndexOf]]''' ( QChar ''ch'', int ''from'' = -1, Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*int '''[[Qt:Документация 4.3.2/qstring#lastIndexOf-3 | lastIndexOf]]''' ( const QRegExp &amp; ''rx'', int ''from'' = -1 ) const
*QString '''[[Qt:Документация 4.3.2/qstring#left | left]]''' ( int ''n'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#leftJustified | leftJustified]]''' ( int ''width'', QChar ''fill'' = QLatin1Char( ' ' ), bool ''truncate'' = false ) const
*int '''[[Qt:Документация 4.3.2/qstring#length | length]]''' () const
*int '''[[Qt:Документация 4.3.2/qstring#localeAwareCompare-2 | localeAwareCompare]]''' ( const QString &amp; ''other'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#mid | mid]]''' ( int ''position'', int ''n'' = -1 ) const
*QString '''[[Qt:Документация 4.3.2/qstring#normalized | normalized]]''' ( NormalizationForm ''mode'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#normalized-2 | normalized]]''' ( NormalizationForm ''mode'', QChar::UnicodeVersion ''version'' ) const
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#prepend | prepend]]''' ( const QString &amp; ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#prepend-2 | prepend]]''' ( const QLatin1String &amp; ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#prepend-3 | prepend]]''' ( const QByteArray &amp; ''ba'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#prepend-4 | prepend]]''' ( const char * ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#prepend-5 | prepend]]''' ( QChar ''ch'' )
*void '''[[Qt:Документация 4.3.2/qstring#push_back | push_back]]''' ( const QString &amp; ''other'' )
*void '''[[Qt:Документация 4.3.2/qstring#push_back-2 | push_back]]''' ( QChar ''ch'' )
*void '''[[Qt:Документация 4.3.2/qstring#push_front | push_front]]''' ( const QString &amp; ''other'' )
*void '''[[Qt:Документация 4.3.2/qstring#push_front-2 | push_front]]''' ( QChar ''ch'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#remove | remove]]''' ( int ''position'', int ''n'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#remove-4 | remove]]''' ( const QString &amp; ''str'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#remove-5 | remove]]''' ( QChar ''ch'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#remove-6 | remove]]''' ( const QRegExp &amp; ''rx'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#replace | replace]]''' ( int ''position'', int ''n'', const QString &amp; ''after'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#replace-6 | replace]]''' ( int ''position'', int ''n'', const QChar * ''unicode'', int ''size'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#replace-7 | replace]]''' ( int ''position'', int ''n'', QChar ''after'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#replace-8 | replace]]''' ( const QString &amp; ''before'', const QString &amp; ''after'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#replace-9 | replace]]''' ( QChar ''ch'', const QString &amp; ''after'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#replace-10 | replace]]''' ( QChar ''before'', QChar ''after'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#replace-11 | replace]]''' ( const QRegExp &amp; ''rx'', const QString &amp; ''after'' )
*void '''[[Qt:Документация 4.3.2/qstring#reserve | reserve]]''' ( int ''size'' )
*void '''[[Qt:Документация 4.3.2/qstring#resize | resize]]''' ( int ''size'' )
*QString '''[[Qt:Документация 4.3.2/qstring#right | right]]''' ( int ''n'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#rightJustified | rightJustified]]''' ( int ''width'', QChar ''fill'' = QLatin1Char( ' ' ), bool ''truncate'' = false ) const
*QString '''[[Qt:Документация 4.3.2/qstring#section | section]]''' ( QChar ''sep'', int ''start'', int ''end'' = -1, SectionFlags ''flags'' = SectionDefault ) const
*QString '''[[Qt:Документация 4.3.2/qstring#section-2 | section]]''' ( const QString &amp; ''sep'', int ''start'', int ''end'' = -1, SectionFlags ''flags'' = SectionDefault ) const
*QString '''[[Qt:Документация 4.3.2/qstring#section-3 | section]]''' ( const QRegExp &amp; ''reg'', int ''start'', int ''end'' = -1, SectionFlags ''flags'' = SectionDefault ) const
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setNum | setNum]]''' ( int ''n'', int ''base'' = 10 )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setNum-2 | setNum]]''' ( uint ''n'', int ''base'' = 10 )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setNum-3 | setNum]]''' ( long ''n'', int ''base'' = 10 )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setNum-4 | setNum]]''' ( ulong ''n'', int ''base'' = 10 )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setNum-5 | setNum]]''' ( qlonglong ''n'', int ''base'' = 10 )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setNum-6 | setNum]]''' ( qulonglong ''n'', int ''base'' = 10 )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setNum-7 | setNum]]''' ( short ''n'', int ''base'' = 10 )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setNum-8 | setNum]]''' ( ushort ''n'', int ''base'' = 10 )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setNum-9 | setNum]]''' ( double ''n'', char ''format'' = 'g', int ''precision'' = 6 )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setNum-10 | setNum]]''' ( float ''n'', char ''format'' = 'g', int ''precision'' = 6 )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setUnicode | setUnicode]]''' ( const QChar * ''unicode'', int ''size'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#setUtf16 | setUtf16]]''' ( const ushort * ''unicode'', int ''size'' )
*QString '''[[Qt:Документация 4.3.2/qstring#simplified | simplified]]''' () const
*int '''[[Qt:Документация 4.3.2/qstring#size | size]]''' () const
*QStringList '''[[Qt:Документация 4.3.2/qstring#split | split]]''' ( const QString &amp; ''sep'', SplitBehavior ''behavior'' = KeepEmptyParts, Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*QStringList '''[[Qt:Документация 4.3.2/qstring#split-2 | split]]''' ( const QChar &amp; ''sep'', SplitBehavior ''behavior'' = KeepEmptyParts, Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*QStringList '''[[Qt:Документация 4.3.2/qstring#split-3 | split]]''' ( const QRegExp &amp; ''rx'', SplitBehavior ''behavior'' = KeepEmptyParts ) const
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#sprintf | sprintf]]''' ( const char * ''cformat'', ... )
*void '''[[Qt:Документация 4.3.2/qstring#squeeze | squeeze]]''' ()
*bool '''[[Qt:Документация 4.3.2/qstring#startsWith | startsWith]]''' ( const QString &amp; ''s'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*bool '''[[Qt:Документация 4.3.2/qstring#startsWith-3 | startsWith]]''' ( const QLatin1String &amp; ''s'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*bool '''[[Qt:Документация 4.3.2/qstring#startsWith-4 | startsWith]]''' ( const QChar &amp; ''c'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive ) const
*QByteArray '''[[Qt:Документация 4.3.2/qstring#toAscii | toAscii]]''' () const
*QString '''[[Qt:Документация 4.3.2/qstring#toCaseFolded | toCaseFolded]]''' () const
*double '''[[Qt:Документация 4.3.2/qstring#toDouble | toDouble]]''' ( bool * ''ok'' = 0 ) const
*float '''[[Qt:Документация 4.3.2/qstring#toFloat | toFloat]]''' ( bool * ''ok'' = 0 ) const
*int '''[[Qt:Документация 4.3.2/qstring#toInt | toInt]]''' ( bool * ''ok'' = 0, int ''base'' = 10 ) const
*QByteArray '''[[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]]''' () const
*QByteArray '''[[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]]''' () const
*long '''[[Qt:Документация 4.3.2/qstring#toLong | toLong]]''' ( bool * ''ok'' = 0, int ''base'' = 10 ) const
*qlonglong '''[[Qt:Документация 4.3.2/qstring#toLongLong | toLongLong]]''' ( bool * ''ok'' = 0, int ''base'' = 10 ) const
*QString '''[[Qt:Документация 4.3.2/qstring#toLower | toLower]]''' () const
*short '''[[Qt:Документация 4.3.2/qstring#toShort | toShort]]''' ( bool * ''ok'' = 0, int ''base'' = 10 ) const
*std::string '''[[Qt:Документация 4.3.2/qstring#toStdString | toStdString]]''' () const
*std::wstring '''[[Qt:Документация 4.3.2/qstring#toStdWString | toStdWString]]''' () const
*uint '''[[Qt:Документация 4.3.2/qstring#toUInt | toUInt]]''' ( bool * ''ok'' = 0, int ''base'' = 10 ) const
*ulong '''[[Qt:Документация 4.3.2/qstring#toULong | toULong]]''' ( bool * ''ok'' = 0, int ''base'' = 10 ) const
*qulonglong '''[[Qt:Документация 4.3.2/qstring#toULongLong | toULongLong]]''' ( bool * ''ok'' = 0, int ''base'' = 10 ) const
*ushort '''[[Qt:Документация 4.3.2/qstring#toUShort | toUShort]]''' ( bool * ''ok'' = 0, int ''base'' = 10 ) const
*QVector<uint> '''[[Qt:Документация 4.3.2/qstring#toUcs4 | toUcs4]]''' () const
*QString '''[[Qt:Документация 4.3.2/qstring#toUpper | toUpper]]''' () const
*QByteArray '''[[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]]''' () const
*int '''[[Qt:Документация 4.3.2/qstring#toWCharArray | toWCharArray]]''' ( wchar_t * ''array'' ) const
*QString '''[[Qt:Документация 4.3.2/qstring#trimmed | trimmed]]''' () const
*void '''[[Qt:Документация 4.3.2/qstring#truncate | truncate]]''' ( int ''position'' )
*const QChar * '''[[Qt:Документация 4.3.2/qstring#unicode | unicode]]''' () const
*const ushort * '''[[Qt:Документация 4.3.2/qstring#utf16 | utf16]]''' () const
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#vsprintf | vsprintf]]''' ( const char * ''cformat'', va_list ''ap'' )
*bool '''[[Qt:Документация 4.3.2/qstring#operator-not-eq | operator!=]]''' ( const QString &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-not-eq-2 | operator!=]]''' ( const QLatin1String &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-not-eq-3 | operator!=]]''' ( const QByteArray &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-not-eq-4 | operator!=]]''' ( const char * ''other'' ) const
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-2b-eq | operator+=]]''' ( const QString &amp; ''other'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-2b-eq-2 | operator+=]]''' ( const QLatin1String &amp; ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-2b-eq-3 | operator+=]]''' ( const QByteArray &amp; ''ba'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-2b-eq-4 | operator+=]]''' ( const char * ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-2b-eq-5 | operator+=]]''' ( char ''ch'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-2b-eq-6 | operator+=]]''' ( QChar ''ch'' )
*bool '''[[Qt:Документация 4.3.2/qstring#operator-lt | operator<]]''' ( const QString &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-lt-2 | operator<]]''' ( const QLatin1String &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-lt-3 | operator<]]''' ( const QByteArray &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-lt-4 | operator<]]''' ( const char * ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-lt-eq | operator<=]]''' ( const QString &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-lt-eq-2 | operator<=]]''' ( const QLatin1String &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-lt-eq-3 | operator<=]]''' ( const QByteArray &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-lt-eq-4 | operator<=]]''' ( const char * ''other'' ) const
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-eq | operator=]]''' ( const QString &amp; ''other'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-eq-3 | operator=]]''' ( const QLatin1String &amp; ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-eq-4 | operator=]]''' ( const QByteArray &amp; ''ba'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-eq-5 | operator=]]''' ( const char * ''str'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-eq-6 | operator=]]''' ( char ''ch'' )
*QString &amp; '''[[Qt:Документация 4.3.2/qstring#operator-eq-7 | operator=]]''' ( QChar ''ch'' )
*bool '''[[Qt:Документация 4.3.2/qstring#operator-eq-eq | operator==]]''' ( const QString &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-eq-eq-2 | operator==]]''' ( const QLatin1String &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-eq-eq-3 | operator==]]''' ( const QByteArray &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-eq-eq-4 | operator==]]''' ( const char * ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-gt | operator>]]''' ( const QString &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-gt-2 | operator>]]''' ( const QLatin1String &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-gt-3 | operator>]]''' ( const QByteArray &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-gt-4 | operator>]]''' ( const char * ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-gt-eq | operator>=]]''' ( const QString &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-gt-eq-2 | operator>=]]''' ( const QLatin1String &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-gt-eq-3 | operator>=]]''' ( const QByteArray &amp; ''other'' ) const
*bool '''[[Qt:Документация 4.3.2/qstring#operator-gt-eq-4 | operator>=]]''' ( const char * ''other'' ) const
*QCharRef '''[[Qt:Документация 4.3.2/qstring#operator-5b-5d | operator[]] ] ''' ( int ''position'' )
*const QChar '''[[Qt:Документация 4.3.2/qstring#operator-5b-5d-2 | operator[]] ] ''' ( int ''position'' ) const
*QCharRef '''[[Qt:Документация 4.3.2/qstring#operator-5b-5d-3 | operator[]] ] ''' ( uint ''position'' )
*const QChar '''[[Qt:Документация 4.3.2/qstring#operator-5b-5d-4 | operator[]] ] ''' ( uint ''position'' ) const
<div id="static-public-members"></div>
===Статические открытые члены===

*int '''[[Qt:Документация 4.3.2/qstring#compare | compare]]''' ( const QString &amp; ''s1'', const QString &amp; ''s2'', Qt::CaseSensitivity ''cs'' )
*int '''[[Qt:Документация 4.3.2/qstring#compare-2 | compare]]''' ( const QString &amp; ''s1'', const QString &amp; ''s2'' )
*int '''[[Qt:Документация 4.3.2/qstring#compare-3 | compare]]''' ( const QString &amp; ''s1'', const QLatin1String &amp; ''s2'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive )
*int '''[[Qt:Документация 4.3.2/qstring#compare-4 | compare]]''' ( const QLatin1String &amp; ''s1'', const QString &amp; ''s2'', Qt::CaseSensitivity ''cs'' = Qt::CaseSensitive )
*QString '''[[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]''' ( const char * ''str'', int ''size'' = -1 )
*QString '''[[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]]''' ( const char * ''str'', int ''size'' = -1 )
*QString '''[[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]]''' ( const char * ''str'', int ''size'' = -1 )
*QString '''[[Qt:Документация 4.3.2/qstring#fromRawData | fromRawData]]''' ( const QChar * ''unicode'', int ''size'' )
*QString '''[[Qt:Документация 4.3.2/qstring#fromStdString | fromStdString]]''' ( const std::string &amp; ''str'' )
*QString '''[[Qt:Документация 4.3.2/qstring#fromStdWString | fromStdWString]]''' ( const std::wstring &amp; ''str'' )
*QString '''[[Qt:Документация 4.3.2/qstring#fromUcs4 | fromUcs4]]''' ( const uint * ''unicode'', int ''size'' = -1 )
*QString '''[[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]]''' ( const char * ''str'', int ''size'' = -1 )
*QString '''[[Qt:Документация 4.3.2/qstring#fromUtf16 | fromUtf16]]''' ( const ushort * ''unicode'', int ''size'' = -1 )
*QString '''[[Qt:Документация 4.3.2/qstring#fromWCharArray | fromWCharArray]]''' ( const wchar_t * ''string'', int ''size'' = -1 )
*int '''[[Qt:Документация 4.3.2/qstring#localeAwareCompare | localeAwareCompare]]''' ( const QString &amp; ''s1'', const QString &amp; ''s2'' )
*QString '''[[Qt:Документация 4.3.2/qstring#number | number]]''' ( long ''n'', int ''base'' = 10 )
*QString '''[[Qt:Документация 4.3.2/qstring#number-2 | number]]''' ( ulong ''n'', int ''base'' = 10 )
*QString '''[[Qt:Документация 4.3.2/qstring#number-3 | number]]''' ( int ''n'', int ''base'' = 10 )
*QString '''[[Qt:Документация 4.3.2/qstring#number-4 | number]]''' ( uint ''n'', int ''base'' = 10 )
*QString '''[[Qt:Документация 4.3.2/qstring#number-5 | number]]''' ( qlonglong ''n'', int ''base'' = 10 )
*QString '''[[Qt:Документация 4.3.2/qstring#number-6 | number]]''' ( qulonglong ''n'', int ''base'' = 10 )
*QString '''[[Qt:Документация 4.3.2/qstring#number-7 | number]]''' ( double ''n'', char ''format'' = 'g', int ''precision'' = 6 )
<div id="related-non-members"></div>
===Связанные не-члены===

*bool '''[[Qt:Документация 4.3.2/qstring#operator-not-eq-44 | operator!=]]''' ( const char * ''s1'', const QString &amp; ''s2'' )
*const QString '''[[Qt:Документация 4.3.2/qstring#operator-2b-8 | operator+]]''' ( const QString &amp; ''s1'', const QString &amp; ''s2'' )
*const QString '''[[Qt:Документация 4.3.2/qstring#operator-2b-25 | operator+]]''' ( const QString &amp; ''s1'', const char * ''s2'' )
*const QString '''[[Qt:Документация 4.3.2/qstring#operator-2b-26 | operator+]]''' ( const char * ''s1'', const QString &amp; ''s2'' )
*const QString '''[[Qt:Документация 4.3.2/qstring#operator-2b-27 | operator+]]''' ( const QString &amp; ''s'', char ''ch'' )
*const QString '''[[Qt:Документация 4.3.2/qstring#operator-2b-28 | operator+]]''' ( char ''ch'', const QString &amp; ''s'' )
*bool '''[[Qt:Документация 4.3.2/qstring#operator-lt-18 | operator<]]''' ( const char * ''s1'', const QString &amp; ''s2'' )
*QDataStream &amp; '''[[Qt:Документация 4.3.2/qstring#operator-lt-lt-56 | operator<<]]''' ( QDataStream &amp; ''stream'', const QString &amp; ''string'' )
*bool '''[[Qt:Документация 4.3.2/qstring#operator-lt-eq-15 | operator<=]]''' ( const char * ''s1'', const QString &amp; ''s2'' )
*bool '''[[Qt:Документация 4.3.2/qstring#operator-eq-eq-60 | operator==]]''' ( const char * ''s1'', const QString &amp; ''s2'' )
*bool '''[[Qt:Документация 4.3.2/qstring#operator-gt-15 | operator>]]''' ( const char * ''s1'', const QString &amp; ''s2'' )
*bool '''[[Qt:Документация 4.3.2/qstring#operator-gt-eq-15 | operator>=]]''' ( const char * ''s1'', const QString &amp; ''s2'' )
*QDataStream &amp; '''[[Qt:Документация 4.3.2/qstring#operator-gt-gt-33 | operator>>]]''' ( QDataStream &amp; ''stream'', QString &amp; ''string'' )
<div id="macros"></div>
===Макросы===

*'''[[Qt:Документация 4.3.2/qstring#QT_NO_CAST_FROM_ASCII | QT_NO_CAST_FROM_ASCII]]'''
*'''[[Qt:Документация 4.3.2/qstring#QT_NO_CAST_TO_ASCII | QT_NO_CAST_TO_ASCII]]'''
<div id="details"></div><hr />
==Подробное описание==

The QString class provides a Unicode character string.

QString stores a string of 16-bit [[Qt:Документация 4.3.2/qchar | QChar]]s, where each [[Qt:Документация 4.3.2/qchar | QChar]] corresponds one Unicode 4.0 character. (Unicode characters with code values above 65535 are stored using surrogate pairs, i.e&#x2e;, two consecutive [[Qt:Документация 4.3.2/qchar | QChar]]s.)

[[Qt:Документация 4.3.2/unicode | Unicode]] is an international standard that supports most of the writing systems in use today. It is a superset of ASCII and Latin-1 (ISO 8859-1), and all the ASCII/Latin-1 characters are available at the same code positions.

Behind the scenes, QString uses [[Qt:Документация 4.3.2/shared#implicit-sharing | implicit sharing]] (copy-on-write) to reduce memory usage and to avoid the needless copying of data. This also helps reduce the inherent overhead of storing 16-bit characters instead of 8-bit characters.

In addition to QString, Qt also provides the [[Qt:Документация 4.3.2/qbytearray | QByteArray]] class to store raw bytes and traditional 8-bit '\0'-terminated strings. For most purposes, QString is the class you want to use. It is used throughout the Qt API, and the Unicode support ensures that your applications will be easy to translate if you want to expand your application's market at some point. The two main cases where [[Qt:Документация 4.3.2/qbytearray | QByteArray]] is appropriate are when you need to store raw binary data, and when memory conservation is critical (e.g&#x2e; with [[Qt:Документация 4.3.2/qtopiacore | Qtopia Core]]).

*[[#initializing-a-string | Initializing a String]]
*[[#manipulating-string-data | Manipulating String Data]]
*[[#querying-string-data | Querying String Data]]
*[[#converting-between-8-bit-strings-and-unicode-strings | Converting Between 8-Bit Strings and Unicode Strings]]
*[[#note-for-c-programmers | Note for C Programmers]]
*[[#distinction-between-null-and-empty-strings | Distinction Between Null and Empty Strings]]
<div id="initializing-a-string"></div>
===Initializing a String===

One way to initialize a QString is simply to pass a <tt>const char *</tt> to its constructor. For example, the following code creates a QString of size 5 containing the data "Hello":
<source lang="cpp-qt">     QString str = "Hello";</source> 
QString converts the <tt>const char *</tt> data into Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function. By default, [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() treats character above 128 as Latin-1 characters, but this can be changed by calling [[Qt:Документация 4.3.2/qtextcodec#setCodecForCStrings | QTextCodec::setCodecForCStrings]]().

In all of the QString functions that take <tt>const char *</tt> parameters, the <tt>const char *</tt> is interpreted as a classic C-style '\0'-terminated string. It is legal for the <tt>const char *</tt> parameter to be 0.

You can also provide string data as an array of [[Qt:Документация 4.3.2/qchar | QChar]]s:
<source lang="cpp-qt">     static const QChar data[4] = { 0x0055, 0x006e, 0x10e3, 0x03a3 };
     QString str(data, 4);</source> 
QString makes a deep copy of the [[Qt:Документация 4.3.2/qchar | QChar]] data, so you can modify it later without experiencing side effects. (If for performance reasons you don't want to take a deep copy of the character data, use [[Qt:Документация 4.3.2/qstring#fromRawData | QString::fromRawData]]() instead.)

Another approach is to set the size of the string using [[Qt:Документация 4.3.2/qstring#resize | resize]]() and to initialize the data character per character. QString uses 0-based indexes, just like C++ arrays. To access the character at a particular index position, you can use [[Qt:Документация 4.3.2/qstring#operator-5b-5d | operator[]] ] (). On non-const strings, [[Qt:Документация 4.3.2/qstring#operator-5b-5d | operator[]] ] () returns a reference to a character that can be used on the left side of an assignment. For example:
<source lang="cpp-qt">     QString str;
     str.resize(4);

     str[0] = QChar('U');
     str[1] = QChar('n');
     str[2] = QChar(0x10e3);
     str[3] = QChar(0x03a3);</source> 
For read-only access, an alternative syntax is to use the [[Qt:Документация 4.3.2/qstring#at | at]]() function:
<source lang="cpp-qt">     QString str;

     for (int i = 0; i < str.size(); ++i) {
         if (str.at(i) >= QChar('a') &amp;&amp; str.at(i) <= QChar('f'))
             qDebug() << "Found character in range [a-f]";
     }</source> 
The [[Qt:Документация 4.3.2/qstring#at | at]]() function can be faster than [[Qt:Документация 4.3.2/qstring#operator-5b-5d | operator[]] ] (), because it never causes a [[Qt:Документация 4.3.2/shared#deep-copy | deep copy]] to occur. Alternatively, use the [[Qt:Документация 4.3.2/qstring#left | left]](), [[Qt:Документация 4.3.2/qstring#right | right]](), or [[Qt:Документация 4.3.2/qstring#mid | mid]]() functions to extract several characters at a time.

A QString can embed '\0' characters ([[Qt:Документация 4.3.2/qchar#SpecialCharacter-enum | QChar::null]]). The [[Qt:Документация 4.3.2/qstring#size | size]]() function always returns the size of the whole string, including embedded '\0' characters.

After a call to the [[Qt:Документация 4.3.2/qstring#resize | resize]]() function, newly allocated characters have undefined values. To set all the characters in the string to a particular value, use the [[Qt:Документация 4.3.2/qstring#fill | fill]]() function.

QString provides dozens of overloads designed to simplify string usage. For example, if you want to compare a QString with a string literal, you can write code like this and it will work as expected:
<source lang="cpp-qt">     QString str;

     if (str == "auto" || str == "extern"
             || str == "static" || str == "register") {
         // ...
     }</source> 
You can also pass string literals to functions that take QStrings as arguments, invoking the QString(const char *) constructor. Similarly, you can pass a QString to a function that takes a <tt>const char *</tt> argument using the [[Qt:Документация 4.3.2/qtglobal#qPrintable | qPrintable]]() macro which returns the given QString as a <tt>const char *</tt>. This is equivalent to calling <QString>.[[Qt:Документация 4.3.2/qstring#toAscii | toAscii]]().[[Qt:Документация 4.3.2/qstring#constData | constData]]().
<div id="manipulating-string-data"></div>
===Manipulating String Data===

QString provides the following basic functions for modifying the character data: [[Qt:Документация 4.3.2/qstring#append | append]](), [[Qt:Документация 4.3.2/qstring#prepend | prepend]](), [[Qt:Документация 4.3.2/qstring#insert | insert]](), [[Qt:Документация 4.3.2/qstring#replace | replace]](), and [[Qt:Документация 4.3.2/qstring#remove | remove]](). For example:
<source lang="cpp-qt">     QString str = "and";
     str.prepend("rock ");     // str == "rock and"
     str.append(" roll");        // str == "rock and roll"
     str.replace(5, 3, "&amp;");   // str == "rock &amp; roll"</source> 
If you are building a QString gradually and know in advance approximately how many characters the QString will contain, you can call [[Qt:Документация 4.3.2/qstring#reserve | reserve]](), asking QString to preallocate a certain amount of memory. You can also call [[Qt:Документация 4.3.2/qstring#capacity | capacity]]() to find out how much memory QString actually allocated.

The [[Qt:Документация 4.3.2/qstring#replace | replace]]() and [[Qt:Документация 4.3.2/qstring#remove | remove]]() functions' first two arguments are the position from which to start erasing and the number of characters that should be erased. If you want to replace all occurrences of a particular substring with another, use one of the two-parameter [[Qt:Документация 4.3.2/qstring#replace | replace]]() overloads.

A frequent requirement is to remove whitespace characters from a string ('\n', '\t', ' ', etc.)&#x2e; If you want to remove whitespace from both ends of a QString, use the [[Qt:Документация 4.3.2/qstring#trimmed | trimmed]]() function. If you want to remove whitespace from both ends and replace multiple consecutive whitespaces with a single space character within the string, use [[Qt:Документация 4.3.2/qstring#simplified | simplified]]().

If you want to find all occurrences of a particular character or substring in a QString, use the [[Qt:Документация 4.3.2/qstring#indexOf | indexOf]]() or [[Qt:Документация 4.3.2/qstring#lastIndexOf | lastIndexOf]]() functions. The former searches forward starting from a given index position, the latter searches backward. Both return the index position of the character or substring if they find it; otherwise, they return -1. For example, here's a typical loop that finds all occurrences of a particular substring:
<source lang="cpp-qt">     QString str = "We must be <b>bold</b>, very <b>bold</b>";
     int j = 0;

     while ((j = str.indexOf("<b>", j)) != -1) {
         qDebug() << "Found <b> tag at index position" << j;
         ++j;
     }</source> 
QString provides many functions for converting numbers into strings and strings into numbers. See the [[Qt:Документация 4.3.2/qstring#arg | arg]]() functions, the [[Qt:Документация 4.3.2/qstring#setNum | setNum]]() functions, the [[Qt:Документация 4.3.2/qstring#number | number]]() static functions, and the [[Qt:Документация 4.3.2/qstring#toInt | toInt]](), [[Qt:Документация 4.3.2/qstring#toDouble | toDouble]](), and similar functions.

To get an upper- or lowercase version of a string use [[Qt:Документация 4.3.2/qstring#toUpper | toUpper]]() or [[Qt:Документация 4.3.2/qstring#toLower | toLower]]().

Lists of strings are handled by the [[Qt:Документация 4.3.2/qstringlist | QStringList]] class. You can split a string into a list of strings using the [[Qt:Документация 4.3.2/qstring#split | split]]() function, and join a list of strings into a single string with an optional separator using [[Qt:Документация 4.3.2/qstringlist#join | QStringList::join]](). You can obtain a list of strings from a string list that contain a particular substring or that match a particular [[Qt:Документация 4.3.2/qregexp | QRegExp]] using the [[Qt:Документация 4.3.2/qlist-qt3#find | QStringList::find]]() function. :
<div id="querying-string-data"></div>
===Querying String Data===

If you want to see if a QString starts or ends with a particular substring use [[Qt:Документация 4.3.2/qstring#startsWith | startsWith]]() or [[Qt:Документация 4.3.2/qstring#endsWith | endsWith]](). If you simply want to check whether a QString contains a particular character or substring, use the [[Qt:Документация 4.3.2/qstring#contains | contains]]() function. If you want to find out how many times a particular character or substring occurs in the string, use [[Qt:Документация 4.3.2/qstring#count | count]]().

QStrings can be compared using overloaded operators such as [[Qt:Документация 4.3.2/qstring#operator-lt | operator<]](), [[Qt:Документация 4.3.2/qstring#operator-lt-eq | operator<=]](), [[Qt:Документация 4.3.2/qstring#operator-eq-eq | operator==]](), [[Qt:Документация 4.3.2/qstring#operator-gt-eq | operator>=]](), and so on. Note that the comparison is based exclusively on the numeric Unicode values of the characters. It is very fast, but is not what a human would expect; the [[Qt:Документация 4.3.2/qstring#localeAwareCompare | QString::localeAwareCompare]]() function is a better choice for sorting user-interface strings.

To obtain a pointer to the actual character data, call [[Qt:Документация 4.3.2/qstring#data | data]]() or [[Qt:Документация 4.3.2/qstring#constData | constData]](). These functions return a pointer to the beginning of the [[Qt:Документация 4.3.2/qchar | QChar]] data. The pointer is guaranteed to remain valid until a non-const function is called on the QString.
<div id="converting-between-8-bit-strings-and-unicode-strings"></div>
===Converting Between 8-Bit Strings and Unicode Strings===

QString provides the following four functions that return a <tt>const char *</tt> version of the string as [[Qt:Документация 4.3.2/qbytearray | QByteArray]]: [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]](), [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]](), [[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]](), and [[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]]().

*[[Qt:Документация 4.3.2/qstring#toAscii | toAscii]]() returns an ASCII encoded 8-bit string.
*[[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]]() returns a Latin-1 (ISO 8859-1) encoded 8-bit string.
*[[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]]() returns a UTF-8 encoded 8-bit string. UTF-8 is a superset of ASCII that supports the entire Unicode character set through multibyte sequences.
*[[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]]() returns an 8-bit string using the system's local encoding.

To convert from one of these encodings, QString provides [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]](), [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]](), [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]](), and [[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]](). Other encodings are supported through the [[Qt:Документация 4.3.2/qtextcodec | QTextCodec]] class.

As mentioned above, QString provides a lot of functions and operators that make it easy to interoperate with <tt>const char *</tt> strings. But this functionality is a double-edged sword: It makes QString more convenient to use if all strings are ASCII or Latin-1, but there is always the risk that an implicit conversion from or to <tt>const char *</tt> is done using the wrong 8-bit encoding. To minimize these risks, you can turn off these implicit conversions by defining the following two preprocessor symbols:

*<tt>QT_NO_CAST_FROM_ASCII</tt> disables automatic conversions from ASCII to Unicode.
*<tt>QT_NO_CAST_TO_ASCII</tt> disables automatic conversion from QString to ASCII.

One way to define these preprocessor symbols globally for your application is to add the following entry to your [[Qt:Документация 4.3.2/qmake-project-files | qmake project file]]:
<source lang="cpp-qt"> DEFINES += QT_NO_CAST_FROM_ASCII \
            QT_NO_CAST_TO_ASCII</source> 
You then need to explicitly call [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]](), [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]](), [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]](), or [[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]]() to construct a QString from an 8-bit string, or use the lightweight [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] class, for example:
<source lang="cpp-qt"> QString url = QLatin1String("http://www.unicode.org/");</source> 
Similarly, you must call [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]](), [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]](), [[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]](), or [[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]]() explicitly to convert the QString to an 8-bit string. (Other encodings are supported through the [[Qt:Документация 4.3.2/qtextcodec | QTextCodec]] class.)


{|  width="100 %" align="center" cellpadding="2" cellspacing="1" border="0"
|- valign="top" class="odd" | 
|<div id="note-for-c-programmers"></div>
===Note for C Programmers===

Due to C++'s type system and the fact that QString is [[Qt:Документация 4.3.2/shared#implicitly-shared | implicitly shared]], QStrings may be treated like <tt>int</tt>s or other basic types. For example:
<source lang="cpp-qt">     QString Widget::boolToString(bool b)
     {
         QString result;
         if (b)
             result = "True";
         else
             result = "False";
         return result;
     }</source> 
The <tt>result</tt> variable, is a normal variable allocated on the stack. When <tt>return</tt> is called, and because we're returning by value, the copy constructor is called and a copy of the string is returned. No actual copying takes place thanks to the implicit sharing.

|}
<div id="distinction-between-null-and-empty-strings"></div>
===Distinction Between Null and Empty Strings===

For historical reasons, QString distinguishes between a null string and an empty string. A ''null'' string is a string that is initialized using QString's default constructor or by passing (const char *)0 to the constructor. An ''empty'' string is any string with size 0. A null string is always empty, but an empty string isn't necessarily null:
<source lang="cpp-qt">     QString().isNull();               // returns true
     QString().isEmpty();              // returns true

     QString("").isNull();             // returns false
     QString("").isEmpty();            // returns true

     QString("abc").isNull();          // returns false
     QString("abc").isEmpty();         // returns false</source> 
All functions except [[Qt:Документация 4.3.2/qstring#isNull | isNull]]() treat null strings the same as empty strings. For example, [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]]().[[Qt:Документация 4.3.2/qstring#constData | constData]]() returns a pointer to a '\0' character for a null string (''not'' a null pointer), and [[Qt:Документация 4.3.2/qstring#QString | QString]]() compares equal to QString(""). We recommend that you always use the [[Qt:Документация 4.3.2/qstring#isEmpty | isEmpty]]() function and avoid [[Qt:Документация 4.3.2/qstring#isNull | isNull]]().

See also [[Qt:Документация 4.3.2/qstring#fromRawData | fromRawData]](), [[Qt:Документация 4.3.2/qchar | QChar]], [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]], [[Qt:Документация 4.3.2/qbytearray | QByteArray]], and [[Qt:Документация 4.3.2/qstringref | QStringRef]].
<hr />
==Описание типов членов==

===<div id="NormalizationForm-enum"></div>enum QString::NormalizationForm===

This enum describes the various normalized forms of Unicode text.


{|  width="100 %" align="center" cellpadding="2" cellspacing="1" border="0"
|-
! width="25%" | Constant
! width="15%" | Value
! width="60%" | Description
|-
| valign="top" | <tt>QString::NormalizationForm_D</tt>
| align="center" valign="top" | <tt>0</tt>
| valign="top" | Canonical Decomposition
|-
| valign="top" | <tt>QString::NormalizationForm_C</tt>
| align="center" valign="top" | <tt>1</tt>
| valign="top" | Canonical Decomposition followed by Canonical Composition
|-
| valign="top" | <tt>QString::NormalizationForm_KD</tt>
| align="center" valign="top" | <tt>2</tt>
| valign="top" | Compatibility Decomposition
|-
| valign="top" | <tt>QString::NormalizationForm_KC</tt>
| align="center" valign="top" | <tt>3</tt>
| valign="top" | Compatibility Decomposition followed by Canonical Composition
|}

See also [[Qt:Документация 4.3.2/qstring#normalized | normalized]]() and [http://www.unicode.org/reports/tr15/ Unicode Standard Annex #15].

===<div id="SectionFlag-enum"></div>enum QString::SectionFlag<br />flags QString::SectionFlags===

This enum specifies flags that can be used to affect various aspects of the [[Qt:Документация 4.3.2/qstring#section | section]]() function's behavior with respect to separators and empty fields.


{|  width="100 %" align="center" cellpadding="2" cellspacing="1" border="0"
|-
! width="25%" | Constant
! width="15%" | Value
! width="60%" | Description
|-
| valign="top" | <tt>QString::SectionDefault</tt>
| align="center" valign="top" | <tt>0x00</tt>
| valign="top" | Empty fields are counted, leading and trailing separators are not included, and the separator is compared case sensitively.
|-
| valign="top" | <tt>QString::SectionSkipEmpty</tt>
| align="center" valign="top" | <tt>0x01</tt>
| valign="top" | Treat empty fields as if they don't exist, i.e&#x2e; they are not considered as far as ''start'' and ''end'' are concerned.
|-
| valign="top" | <tt>QString::SectionIncludeLeadingSep</tt>
| align="center" valign="top" | <tt>0x02</tt>
| valign="top" | Include the leading separator (if any) in the result string.
|-
| valign="top" | <tt>QString::SectionIncludeTrailingSep</tt>
| align="center" valign="top" | <tt>0x04</tt>
| valign="top" | Include the trailing separator (if any) in the result string.
|-
| valign="top" | <tt>QString::SectionCaseInsensitiveSeps</tt>
| align="center" valign="top" | <tt>0x08</tt>
| valign="top" | Compare the separator case-insensitively.
|}

The SectionFlags type is a typedef for [[Qt:Документация 4.3.2/qflags | QFlags]]<SectionFlag>. It stores an OR combination of SectionFlag values.

See also [[Qt:Документация 4.3.2/qstring#section | section]]().

===<div id="SplitBehavior-enum"></div>enum QString::SplitBehavior===

This enum specifies how the [[Qt:Документация 4.3.2/qstring#split | split]]() function should behave with respect to empty strings.


{|  width="100 %" align="center" cellpadding="2" cellspacing="1" border="0"
|-
! width="25%" | Constant
! width="15%" | Value
! width="60%" | Description
|-
| valign="top" | <tt>QString::KeepEmptyParts</tt>
| align="center" valign="top" | <tt>0</tt>
| valign="top" | If a field is empty, keep it in the result.
|-
| valign="top" | <tt>QString::SkipEmptyParts</tt>
| align="center" valign="top" | <tt>1</tt>
| valign="top" | If a field is empty, don't include it in the result.
|}

See also [[Qt:Документация 4.3.2/qstring#split | split]]().
<hr />
==Описание функций-членов==

===<div id="QString"></div>QString::QString ()===

Constructs a null string. Null strings are also empty.

See also [[Qt:Документация 4.3.2/qstring#isEmpty | isEmpty]]().

===<div id="QString-2"></div>QString::QString ( const [[Qt:Документация 4.3.2/qchar | QChar]] * ''unicode'', int ''size'' )===

Constructs a string initialized with the first ''size'' characters of the [[Qt:Документация 4.3.2/qchar | QChar]] array ''unicode''.

[[Qt:Документация 4.3.2/qstring | QString]] makes a deep copy of the string data.

===<div id="QString-3"></div>QString::QString ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'' )===

Constructs a string of size 1 containing the character ''ch''.

===<div id="QString-4"></div>QString::QString ( int ''size'', [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'' )===

Constructs a string of the given ''size'' with every character set to ''ch''.

See also [[Qt:Документация 4.3.2/qstring#fill | fill]]().

===<div id="QString-5"></div>QString::QString ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''str'' )===

Constructs a copy of the Latin-1 string ''str''.

See also [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]]().

===<div id="QString-6"></div>QString::QString ( const QString &amp; ''other'' )===

Constructs a copy of ''other''.

This operation takes [[Qt:Документация 4.3.2/containers#constant-time | constant time]], because [[Qt:Документация 4.3.2/qstring | QString]] is [[Qt:Документация 4.3.2/shared#implicitly-shared | implicitly shared]]. This makes returning a [[Qt:Документация 4.3.2/qstring | QString]] from a function very fast. If a shared instance is modified, it will be copied (copy-on-write), and that takes [[Qt:Документация 4.3.2/containers#linear-time | linear time]].

See also [[Qt:Документация 4.3.2/qstring#operator-eq | operator=]]().

===<div id="QString-7"></div>QString::QString ( const char * ''str'' )===

Constructs a string initialized with the ASCII string ''str''. The given const char pointer is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this constructor by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

See also [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]](), [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]](), [[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]](), and [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]]().

===<div id="QString-8"></div>QString::QString ( const [[Qt:Документация 4.3.2/qbytearray | QByteArray]] &amp; ''ba'' )===

Constructs a string initialized with the byte array ''ba''. The given byte array is converted to Unicode using [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]](). Stops copying at the first 0 character, otherwise copies the entire byte array.

You can disable this constructor by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

See also [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]](), [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]](), [[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]](), and [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]]().

===<div id="dtor.QString"></div>QString::~QString ()===

Destroys the string.

===<div id="append"></div>QString &amp; QString::append ( const QString &amp; ''str'' )===

Appends the string ''str'' onto the end of this string.

Example:
<source lang="cpp-qt">     QString x = "free";
     QString y = "dom";

     x.append(y);
     // x == "freedom"</source> 
This is the same as using the [[Qt:Документация 4.3.2/qstring#insert | insert]]() function:
<source lang="cpp-qt">     x.insert(x.size(), y);</source> 
The append() function is typically very fast ([[Qt:Документация 4.3.2/containers#constant-time | constant time]]), because [[Qt:Документация 4.3.2/qstring | QString]] preallocates extra space at the end of the string data so it can grow without reallocating the entire string each time.

See also [[Qt:Документация 4.3.2/qstring#operator-2b-eq | operator+=]](), [[Qt:Документация 4.3.2/qstring#prepend | prepend]](), and [[Qt:Документация 4.3.2/qstring#insert | insert]]().

===<div id="append-2"></div>QString &amp; QString::append ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''str'' )===

This is an overloaded member function, provided for convenience.

Appends the Latin-1 string ''str'' to this string.

===<div id="append-3"></div>QString &amp; QString::append ( const [[Qt:Документация 4.3.2/qbytearray | QByteArray]] &amp; ''ba'' )===

This is an overloaded member function, provided for convenience.

Appends the byte array ''ba'' to this string. The given byte array is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this function by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="append-4"></div>QString &amp; QString::append ( const char * ''str'' )===

This is an overloaded member function, provided for convenience.

Appends the string ''str'' to this string. The given const char pointer is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this function by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="append-5"></div>QString &amp; QString::append ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'' )===

This is an overloaded member function, provided for convenience.

Appends the character ''ch'' to this string.

===<div id="arg"></div>QString QString::arg ( const QString &amp; ''a'', int ''fieldWidth'' = 0, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This function returns a copy of this string where ''a'' replaces the lowest numbered occurrence of <tt>%1</tt>, <tt>%2</tt>, ..&#x2e;, <tt>%99</tt>.

The ''fieldWidth'' value specifies the minimum amount of space that ''a'' is padded to and filled with the character ''fillChar''. A positive value will produce right-aligned text, whereas a negative value will produce left-aligned text.

The following example shows how we could create a 'status' string when processing a list of files:
<source lang="cpp-qt">     QString i;           // current file's number
     QString total;       // number of files to process
     QString fileName;    // current file's name

     QString status = QString("Processing file %1 of %2: %3")
                     .arg(i).arg(total).arg(fileName);</source> 
One advantage of using arg() over [[Qt:Документация 4.3.2/qstring#sprintf | sprintf]]() is that the order of arguments may need to change in other languages, when the application is translated.

If there is no place marker (<tt>%1</tt>, <tt>%2</tt>, etc.), a warning message is output and the result is undefined. Note that only placeholders between <tt>%1</tt> and <tt>%99</tt> are supported.

===<div id="arg-2"></div>QString QString::arg ( const QString &amp; ''a1'', const QString &amp; ''a2'' ) const===

This is an overloaded member function, provided for convenience.

This is the same as <tt>str.arg(a1).arg(a2)</tt>, except that the strings ''a1'' and ''a2'' are replaced in one pass. This can make a difference if ''a1'' contains e.g&#x2e; <tt>%1</tt>:
<source lang="cpp-qt">     QString str;
     str = "%1 %2";

     str.arg("%1f", "Hello");        // returns "%1f Hello"
     str.arg("%1f").arg("Hello");    // returns "Hellof"</source> 
===<div id="arg-3"></div>QString QString::arg ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'' ) const===

This is an overloaded member function, provided for convenience.

This is the same as calling <tt>str.arg(a1).arg(a2).arg(a3)</tt>, except that the strings ''a1'', ''a2'' and ''a3'' are replaced in one pass.

===<div id="arg-4"></div>QString QString::arg ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'' ) const===

This is an overloaded member function, provided for convenience.

This is the same as calling <tt>str.arg(a1).arg(a2).arg(a3).arg(a4)</tt>, except that the strings ''a1'', ''a2'', ''a3'' and ''a4'' are replaced in one pass.

===<div id="arg-5"></div>QString QString::arg ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'', const QString &amp; ''a5'' ) const===

This is an overloaded member function, provided for convenience.

This is the same as calling <tt>str.arg(a1).arg(a2).arg(a3).arg(a4).arg(a5)</tt>, except that the strings ''a1'', ''a2'', ''a3'', ''a4'', and ''a5'' are replaced in one pass.

===<div id="arg-6"></div>QString QString::arg ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'', const QString &amp; ''a5'', const QString &amp; ''a6'' ) const===

This is an overloaded member function, provided for convenience.

This is the same as calling <tt>str.arg(a1).arg(a2).arg(a3).arg(a4).arg(a5).arg(a6))</tt>, except that the strings ''a1'', ''a2'', ''a3'', ''a4'', ''a5'', and ''a6'' are replaced in one pass.

===<div id="arg-7"></div>QString QString::arg ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'', const QString &amp; ''a5'', const QString &amp; ''a6'', const QString &amp; ''a7'' ) const===

This is an overloaded member function, provided for convenience.

This is the same as calling <tt>str.arg(a1).arg(a2).arg(a3).arg(a4).arg(a5).arg(a6).arg(a7)</tt>, except that the strings ''a1'', ''a2'', ''a3'', ''a4'', ''a5'', ''a6'', and ''a7'' are replaced in one pass.

===<div id="arg-8"></div>QString QString::arg ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'', const QString &amp; ''a5'', const QString &amp; ''a6'', const QString &amp; ''a7'', const QString &amp; ''a8'' ) const===

This is an overloaded member function, provided for convenience.

This is the same as calling <tt>str.arg(a1).arg(a2).arg(a3).arg(a4).arg(a5).arg(a6).arg(a7).arg(a8)</tt>, except that the strings ''a1'', ''a2'', ''a3'', ''a4'', ''a5'', ''a6'', ''a7'', and ''a8'' are replaced in one pass.

===<div id="arg-9"></div>QString QString::arg ( const QString &amp; ''a1'', const QString &amp; ''a2'', const QString &amp; ''a3'', const QString &amp; ''a4'', const QString &amp; ''a5'', const QString &amp; ''a6'', const QString &amp; ''a7'', const QString &amp; ''a8'', const QString &amp; ''a9'' ) const===

This is an overloaded member function, provided for convenience.

This is the same as calling <tt>str.arg(a1).arg(a2).arg(a3).arg(a4).arg(a5).arg(a6).arg(a7).arg(a8).arg(a9)</tt>, except that the strings ''a1'', ''a2'', ''a3'', ''a4'', ''a5'', ''a6'', ''a7'', ''a8'', and ''a9'' are replaced in one pass.

===<div id="arg-10"></div>QString QString::arg ( int ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This is an overloaded member function, provided for convenience.

The ''a'' argument is expressed in base ''base'', which is 10 by default and must be between 2 and 36. For bases other than 10, ''a'' is treated as an unsigned integer.

The ''fieldWidth'' value specifies the minimum amount of space that ''a'' is padded to and filled with the character ''fillChar''. A positive value will produce a right-aligned number, whereas a negative value will produce a left-aligned number.

The '%' can be followed by an 'L', in which case the sequence is replaced with a localized representation of ''a''. The conversion uses the default locale, set by [[Qt:Документация 4.3.2/qlocale#setDefault | QLocale::setDefault]](). If no default locale was specified, the "C" locale is used. The 'L' flag is ignored if ''base'' is not 10.
<source lang="cpp-qt">     QString str;
     str = QString("Decimal 63 is %1 in hexadecimal")
             .arg(63, 0, 16);
     // str == "Decimal 63 is 3f in hexadecimal"

     QLocale::setDefault(QLocale(QLocale::English, QLocale::UnitedStates));
     str = QString("%1 %L2 %L3")
             .arg(12345)
             .arg(12345)
             .arg(12345, 0, 16);
     // str == "12345 12,345 3039"</source> 
===<div id="arg-11"></div>QString QString::arg ( [[Qt:Документация 4.3.2/qtglobal#uint-typedef | uint]] ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This is an overloaded member function, provided for convenience.

The ''base'' argument specifies the base to use when converting the integer ''a'' into a string. The base must be between 2 and 36.

===<div id="arg-12"></div>QString QString::arg ( long ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This is an overloaded member function, provided for convenience.

The ''fieldWidth'' value specifies the minimum amount of space that ''a'' is padded to and filled with the character ''fillChar''. A positive value will produce a right-aligned number, whereas a negative value will produce a left-aligned number.

The ''a'' argument is expressed in the given ''base'', which is 10 by default and must be between 2 and 36.

The '%' can be followed by an 'L', in which case the sequence is replaced with a localized representation of ''a''. The conversion uses the default locale. The default locale is determined from the system's locale settings at application startup. It can be changed using [[Qt:Документация 4.3.2/qlocale#setDefault | QLocale::setDefault]](). The 'L' flag is ignored if ''base'' is not 10.
<source lang="cpp-qt">     QString str;
     str = QString("Decimal 63 is %1 in hexadecimal")
             .arg(63, 0, 16);
     // str == "Decimal 63 is 3f in hexadecimal"

     QLocale::setDefault(QLocale(QLocale::English, QLocale::UnitedStates));
     str = QString("%1 %L2 %L3")
             .arg(12345)
             .arg(12345)
             .arg(12345, 0, 16);
     // str == "12345 12,345 3039"</source> 
===<div id="arg-13"></div>QString QString::arg ( [[Qt:Документация 4.3.2/qtglobal#ulong-typedef | ulong]] ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This is an overloaded member function, provided for convenience.

The ''base'' argument specifies the base to use when converting the integer ''a'' into a string. The base must be between 2 and 36, with 8 giving octal, 10 decimal, and 16 hexadecimal numbers.

===<div id="arg-14"></div>QString QString::arg ( [[Qt:Документация 4.3.2/qtglobal#qlonglong-typedef | qlonglong]] ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This is an overloaded member function, provided for convenience.

The ''base'' argument specifies the base to use when converting the integer ''a'' into a string. The base must be between 2 and 36, with 8 giving octal, 10 decimal, and 16 hexadecimal numbers.

===<div id="arg-15"></div>QString QString::arg ( [[Qt:Документация 4.3.2/qtglobal#qulonglong-typedef | qulonglong]] ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This is an overloaded member function, provided for convenience.

The ''base'' argument specifies the base to use when converting the integer ''a'' into a string. ''base'' must be between 2 and 36, with 8 giving octal, 10 decimal, and 16 hexadecimal numbers.

===<div id="arg-16"></div>QString QString::arg ( short ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This is an overloaded member function, provided for convenience.

The ''base'' argument specifies the base to use when converting the integer ''a'' into a string. The base must be between 2 and 36, with 8 giving octal, 10 decimal, and 16 hexadecimal numbers.

===<div id="arg-17"></div>QString QString::arg ( [[Qt:Документация 4.3.2/qtglobal#ushort-typedef | ushort]] ''a'', int ''fieldWidth'' = 0, int ''base'' = 10, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This is an overloaded member function, provided for convenience.

The ''base'' argument specifies the base to use when converting the integer ''a'' into a string. The base must be between 2 and 36, with 8 giving octal, 10 decimal, and 16 hexadecimal numbers.

===<div id="arg-18"></div>QString QString::arg ( [[Qt:Документация 4.3.2/qchar | QChar]] ''a'', int ''fieldWidth'' = 0, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This is an overloaded member function, provided for convenience.

===<div id="arg-19"></div>QString QString::arg ( char ''a'', int ''fieldWidth'' = 0, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This is an overloaded member function, provided for convenience.

The ''a'' argument is interpreted as a Latin-1 character.

===<div id="arg-20"></div>QString QString::arg ( double ''a'', int ''fieldWidth'' = 0, char ''format'' = 'g', int ''precision'' = -1, const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''fillChar'' = QLatin1Char( ' ' ) ) const===

This is an overloaded member function, provided for convenience.
<div id="arg-formats"></div>
Argument ''a'' is formatted according to the specified ''format'', which is 'g' by default and can be any of the following:


{|  width="100 %" align="center" cellpadding="2" cellspacing="1" border="0"
|- valign="top" class="qt-style" | 
!Format
!Meaning
|- valign="top" class="odd" | 
|<tt>e</tt>
|format as [-]9.9e[+|-]999
|- valign="top" class="even" | 
|<tt>E</tt>
|format as [-]9.9E[+|-]999
|- valign="top" class="odd" | 
|<tt>f</tt>
|format as [-]9.9
|- valign="top" class="even" | 
|<tt>g</tt>
|use <tt>e</tt> or <tt>f</tt> format, whichever is the most concise
|- valign="top" class="odd" | 
|<tt>G</tt>
|use <tt>E</tt> or <tt>f</tt> format, whichever is the most concise
|}

With 'e', 'E', and 'f', ''precision'' is the number of digits after the decimal point. With 'g' and 'G', ''precision'' is the maximum number of significant digits (trailing zeroes are omitted).
<source lang="cpp-qt"> double d = 12.34;
 QString str = QString("delta: %1").arg(d, 0, 'E', 3);
 // str == "delta: 1.234E+01"</source> 
The '%' can be followed by an 'L', in which case the sequence is replaced with a localized representation of ''a''. The conversion uses the default locale, set by QLocale::setDefaultLocale(). If no default locale was specified, the "C" locale is used.

See also [[Qt:Документация 4.3.2/qlocale#toString | QLocale::toString]]().

===<div id="at"></div>const [[Qt:Документация 4.3.2/qchar | QChar]] QString::at ( int ''position'' ) const===

Returns the character at the given index ''position'' in the string.

The ''position'' must be a valid index position in the string (i.e&#x2e;, 0 <= ''position'' < [[Qt:Документация 4.3.2/qstring#size | size]]()).

See also [[Qt:Документация 4.3.2/qstring#operator-5b-5d | operator[]] ] ().

===<div id="capacity"></div>int QString::capacity () const===

Returns the maximum number of characters that can be stored in the string without forcing a reallocation.

The sole purpose of this function is to provide a means of fine tuning [[Qt:Документация 4.3.2/qstring | QString]]'s memory usage. In general, you will rarely ever need to call this function. If you want to know how many characters are in the string, call [[Qt:Документация 4.3.2/qstring#size | size]]().

See also [[Qt:Документация 4.3.2/qstring#reserve | reserve]]() and [[Qt:Документация 4.3.2/qstring#squeeze | squeeze]]().

===<div id="chop"></div>void QString::chop ( int ''n'' )===

Removes ''n'' characters from the end of the string.

If ''n'' is greater than [[Qt:Документация 4.3.2/qstring#size | size]](), the result is an empty string.

Example:
<source lang="cpp-qt">     QString str("LOGOUT\r\n");
     str.chop(2);
     // str == "LOGOUT"</source> 
If you want to remove characters from the ''beginning'' of the string, use [[Qt:Документация 4.3.2/qstring#remove | remove]]() instead.

See also [[Qt:Документация 4.3.2/qstring#truncate | truncate]](), [[Qt:Документация 4.3.2/qstring#resize | resize]](), and [[Qt:Документация 4.3.2/qstring#remove | remove]]().

===<div id="clear"></div>void QString::clear ()===

Clears the contents of the string and makes it empty.

See also [[Qt:Документация 4.3.2/qstring#resize | resize]]() and [[Qt:Документация 4.3.2/qstring#isEmpty | isEmpty]]().

===<div id="compare"></div>int QString::compare ( const QString &amp; ''s1'', const QString &amp; ''s2'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' )  <tt> [static]</tt>===

Compares ''s1'' with ''s2'' and returns an integer less than, equal to, or greater than zero if ''s1'' is less than, equal to, or greater than ''s2''.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]], the comparison is case sensitive; otherwise the comparison is case insensitive.

Case sensitive comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-visible strings with [[Qt:Документация 4.3.2/qstring#localeAwareCompare | localeAwareCompare]]().
<source lang="cpp-qt">     int x = QString::compare("aUtO", "AuTo", Qt::CaseInsensitive);  // x == 0
     int y = QString::compare("auto", "Car", Qt::CaseSensitive);     // y > 0
     int z = QString::compare("auto", "Car", Qt::CaseInsensitive);   // z < 0</source> 
This function was introduced in Qt 4.2.

See also [[Qt:Документация 4.3.2/qstring#operator-eq-eq | operator==]](), [[Qt:Документация 4.3.2/qstring#operator-lt | operator<]](), and [[Qt:Документация 4.3.2/qstring#operator-gt | operator>]]().

===<div id="compare-2"></div>int QString::compare ( const QString &amp; ''s1'', const QString &amp; ''s2'' )  <tt> [static]</tt>===

This is an overloaded member function, provided for convenience.

Performs a case sensitive compare of ''s1'' and ''s2''.

===<div id="compare-3"></div>int QString::compare ( const QString &amp; ''s1'', const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''s2'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive )  <tt> [static]</tt>===

This is an overloaded member function, provided for convenience.

Performs a comparison of ''s1'' and ''s2'', using the case sensitivity setting ''cs''.

This function was introduced in Qt 4.2.

===<div id="compare-4"></div>int QString::compare ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''s1'', const QString &amp; ''s2'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive )  <tt> [static]</tt>===

This is an overloaded member function, provided for convenience.

Performs a comparison of ''s1'' and ''s2'', using the case sensitivity setting ''cs''.

This function was introduced in Qt 4.2.

===<div id="compare-5"></div>int QString::compare ( const QString &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

Lexically compares this string with the ''other'' string and returns an integer less than, equal to, or greater than zero if this string is less than, equal to, or greater than the other string.

Equivalent to <tt>compare(*this, other)</tt>.

===<div id="compare-6"></div>int QString::compare ( const QString &amp; ''other'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' ) const===

This is an overloaded member function, provided for convenience.

Same as compare(*this, ''other'', ''cs'').

This function was introduced in Qt 4.2.

===<div id="compare-7"></div>int QString::compare ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''other'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

This is an overloaded member function, provided for convenience.

Same as compare(*this, ''other'', ''cs'').

This function was introduced in Qt 4.2.

===<div id="constData"></div>const [[Qt:Документация 4.3.2/qchar | QChar]] * QString::constData () const===

Returns a pointer to the data stored in the [[Qt:Документация 4.3.2/qstring | QString]]. The pointer can be used to access the characters that compose the string. For convenience, the data is '\0'-terminated.

Note that the pointer remains valid only as long as the string is not modified.

See also [[Qt:Документация 4.3.2/qstring#data | data]]() and [[Qt:Документация 4.3.2/qstring#operator-5b-5d | operator[]] ] ().

===<div id="contains"></div>bool QString::contains ( const QString &amp; ''str'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

Returns true if this string contains an occurrence of the string ''str''; otherwise returns false.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]] (the default), the search is case sensitive; otherwise the search is case insensitive.

Example:
<source lang="cpp-qt">     QString str = "Peter Pan";
     str.contains("peter", Qt::CaseInsensitive);    // returns true</source> 
See also [[Qt:Документация 4.3.2/qstring#indexOf | indexOf]]() and [[Qt:Документация 4.3.2/qstring#count | count]]().

===<div id="contains-4"></div>bool QString::contains ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

This is an overloaded member function, provided for convenience.

Returns true if this string contains an occurrence of the character ''ch''; otherwise returns false.

===<div id="contains-5"></div>bool QString::contains ( const [[Qt:Документация 4.3.2/qregexp | QRegExp]] &amp; ''rx'' ) const===

This is an overloaded member function, provided for convenience.

Returns true if the regular expression ''rx'' matches somewhere in this string; otherwise returns false.

===<div id="count"></div>int QString::count ( const QString &amp; ''str'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

Returns the number of (potentially overlapping) occurrences of the string ''str'' in this string.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]] (the default), the search is case sensitive; otherwise the search is case insensitive.

See also [[Qt:Документация 4.3.2/qstring#contains | contains]]() and [[Qt:Документация 4.3.2/qstring#indexOf | indexOf]]().

===<div id="count-2"></div>int QString::count ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

This is an overloaded member function, provided for convenience.

Returns the number of occurrences of character ''ch'' in the string.

===<div id="count-3"></div>int QString::count ( const [[Qt:Документация 4.3.2/qregexp | QRegExp]] &amp; ''rx'' ) const===

This is an overloaded member function, provided for convenience.

Returns the number of times the regular expression ''rx'' matches in the string.

This function counts overlapping matches, so in the example below, there are four instances of "ana" or "ama":
<source lang="cpp-qt">     QString str = "banana and panama";
     str.count(QRegExp("a[nm]a"));    // returns 4</source> 
===<div id="count-4"></div>int QString::count () const===

This is an overloaded member function, provided for convenience.

Same as [[Qt:Документация 4.3.2/qstring#size | size]]().

===<div id="data"></div>[[Qt:Документация 4.3.2/qchar | QChar]] * QString::data ()===

Returns a pointer to the data stored in the [[Qt:Документация 4.3.2/qstring | QString]]. The pointer can be used to access and modify the characters that compose the string. For convenience, the data is '\0'-terminated.

Example:
<source lang="cpp-qt">     QString str = "Hello world";
     QChar *data = str.data();
     while (data) {
         qDebug() << data->unicode();
         ++data;
     }</source> 
Note that the pointer remains valid only as long as the string is not modified by other means. For read-only access, [[Qt:Документация 4.3.2/qstring#constData | constData]]() is faster because it never causes a [[Qt:Документация 4.3.2/shared#deep-copy | deep copy]] to occur.

See also [[Qt:Документация 4.3.2/qstring#constData | constData]]() and [[Qt:Документация 4.3.2/qstring#operator-5b-5d | operator[]] ] ().

===<div id="data-2"></div>const [[Qt:Документация 4.3.2/qchar | QChar]] * QString::data () const===

This is an overloaded member function, provided for convenience.

===<div id="endsWith"></div>bool QString::endsWith ( const QString &amp; ''s'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

Returns true if the string ends with ''s''; otherwise returns false.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]] (the default), the search is case sensitive; otherwise the search is case insensitive.
<source lang="cpp-qt">     QString str = "Bananas";
     str.endsWith("anas");         // returns true
     str.endsWith("pple");         // returns false</source> 
See also [[Qt:Документация 4.3.2/qstring#startsWith | startsWith]]().

===<div id="endsWith-3"></div>bool QString::endsWith ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''s'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

This is an overloaded member function, provided for convenience.

===<div id="endsWith-4"></div>bool QString::endsWith ( const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''c'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

This is an overloaded member function, provided for convenience.

Returns true if the string ends with ''c''; otherwise returns false.

===<div id="fill"></div>QString &amp; QString::fill ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'', int ''size'' = -1 )===

Sets every character in the string to character ''ch''. If ''size'' is different from -1 (the default), the string is resized to ''size'' beforehand.

Example:
<source lang="cpp-qt">     QString str = "Berlin";
     str.fill('z');
     // str == "zzzzzz"

     str.fill('A', 2);
     // str == "AA"</source> 
See also [[Qt:Документация 4.3.2/qstring#resize | resize]]().

===<div id="fromAscii"></div>QString QString::fromAscii ( const char * ''str'', int ''size'' = -1 )  <tt> [static]</tt>===

Returns a [[Qt:Документация 4.3.2/qstring | QString]] initialized with the first ''size'' characters of the 8-bit ASCII string ''str''.

If ''size'' is -1 (the default), it is taken to be qstrlen(''str'').

If a codec has been set using [[Qt:Документация 4.3.2/qtextcodec#setCodecForCStrings | QTextCodec::setCodecForCStrings]](), it is used to convert ''str'' to Unicode; otherwise this function does the same as [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]]().

See also [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]](), [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]](), [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]](), and [[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]]().

===<div id="fromLatin1"></div>QString QString::fromLatin1 ( const char * ''str'', int ''size'' = -1 )  <tt> [static]</tt>===

Returns a [[Qt:Документация 4.3.2/qstring | QString]] initialized with the first ''size'' characters of the Latin-1 string ''str''.

If ''size'' is -1 (the default), it is taken to be qstrlen(''str'').

See also [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]](), [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]](), [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]](), and [[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]]().

===<div id="fromLocal8Bit"></div>QString QString::fromLocal8Bit ( const char * ''str'', int ''size'' = -1 )  <tt> [static]</tt>===

Returns a [[Qt:Документация 4.3.2/qstring | QString]] initialized with the first ''size'' characters of the 8-bit string ''str''.

If ''size'' is -1 (the default), it is taken to be qstrlen(''str'').

[[Qt:Документация 4.3.2/qtextcodec#codecForLocale | QTextCodec::codecForLocale]]() is used to perform the conversion from Unicode.

See also [[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]](), [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]](), [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]](), and [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]]().

===<div id="fromRawData"></div>QString QString::fromRawData ( const [[Qt:Документация 4.3.2/qchar | QChar]] * ''unicode'', int ''size'' )  <tt> [static]</tt>===

Constructs a [[Qt:Документация 4.3.2/qstring | QString]] that uses the first ''size'' Unicode characters in the array ''unicode''. The data in ''unicode'' is ''not'' copied. The caller must be able to guarantee that ''unicode'' will not be deleted or modified as long as the [[Qt:Документация 4.3.2/qstring | QString]] (or an unmodified copy of it) exists.

Any attempts to modify the [[Qt:Документация 4.3.2/qstring | QString]] or copies of it will cause it to create a deep copy of the data, ensuring that the raw data isn't modified.

Here's an example of how we can use a [[Qt:Документация 4.3.2/qregexp | QRegExp]] on raw data in memory without requiring to copy the data into a [[Qt:Документация 4.3.2/qstring | QString]]:
<source lang="cpp-qt">      QRegExp pattern;
      static const QChar unicode[] = {
              0x005A, 0x007F, 0x00A4, 0x0060,
              0x1009, 0x0020, 0x0020};
      int size = sizeof(unicode) / sizeof(QChar);

      QString str = QString::fromRawData(unicode, size);
      if (str.contains(QRegExp(pattern))) {
          // ...
      }</source> 
'''Warning:''' A string created with fromRawData() is ''not'' '\0'-terminated, unless the raw data contains a '\0' character at position ''size''. This means [[Qt:Документация 4.3.2/qstring#unicode | unicode]]() will ''not'' return a '\0'-terminated string (although [[Qt:Документация 4.3.2/qstring#utf16 | utf16]]() does, at the cost of copying the raw data).

See also [[Qt:Документация 4.3.2/qstring#fromUtf16 | fromUtf16]]().

===<div id="fromStdString"></div>QString QString::fromStdString ( const std::string &amp; ''str'' )  <tt> [static]</tt>===

Returns a copy of the ''str'' string. The given string is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

This constructor is only available if Qt is configured with STL compatibility enabled.

See also [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]](), [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]](), [[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]](), and [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]]().

===<div id="fromStdWString"></div>QString QString::fromStdWString ( const std::wstring &amp; ''str'' )  <tt> [static]</tt>===

Returns a copy of the ''str'' string. The given string is assumed to be encoded in utf16 if the size of wchar_t is 2 bytes (e.g&#x2e; on windows) and ucs4 if the size of wchar_t is 4 bytes (most Unix systems).

This method is only available if Qt is configured with STL compatibility enabled.

See also [[Qt:Документация 4.3.2/qstring#fromUtf16 | fromUtf16]](), [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]](), [[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]](), [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]](), and [[Qt:Документация 4.3.2/qstring#fromUcs4 | fromUcs4]]().

===<div id="fromUcs4"></div>QString QString::fromUcs4 ( const [[Qt:Документация 4.3.2/qtglobal#uint-typedef | uint]] * ''unicode'', int ''size'' = -1 )  <tt> [static]</tt>===

Returns a [[Qt:Документация 4.3.2/qstring | QString]] initialized with the first ''size'' characters of the Unicode string ''unicode'' (ISO-10646-UCS-4 encoded).

If ''size'' is -1 (the default), ''unicode'' must be terminated with a 0.

This function was introduced in Qt 4.2.

See also [[Qt:Документация 4.3.2/qstring#toUcs4 | toUcs4]](), [[Qt:Документация 4.3.2/qstring#fromUtf16 | fromUtf16]](), [[Qt:Документация 4.3.2/qstring#utf16 | utf16]](), [[Qt:Документация 4.3.2/qstring#setUtf16 | setUtf16]](), and [[Qt:Документация 4.3.2/qstring#fromWCharArray | fromWCharArray]]().

===<div id="fromUtf8"></div>QString QString::fromUtf8 ( const char * ''str'', int ''size'' = -1 )  <tt> [static]</tt>===

Returns a [[Qt:Документация 4.3.2/qstring | QString]] initialized with the first ''size'' bytes of the UTF-8 string ''str''.

If ''size'' is -1 (the default), it is taken to be qstrlen(''str'').

See also [[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]](), [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]](), [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]](), and [[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]]().

===<div id="fromUtf16"></div>QString QString::fromUtf16 ( const [[Qt:Документация 4.3.2/qtglobal#ushort-typedef | ushort]] * ''unicode'', int ''size'' = -1 )  <tt> [static]</tt>===

Returns a [[Qt:Документация 4.3.2/qstring | QString]] initialized with the first ''size'' characters of the Unicode string ''unicode'' (ISO-10646-UTF-16 encoded).

If ''size'' is -1 (the default), ''unicode'' must be terminated with a 0.

[[Qt:Документация 4.3.2/qstring | QString]] makes a deep copy of the Unicode data.

See also [[Qt:Документация 4.3.2/qstring#utf16 | utf16]]() and [[Qt:Документация 4.3.2/qstring#setUtf16 | setUtf16]]().

===<div id="fromWCharArray"></div>QString QString::fromWCharArray ( const wchar_t * ''string'', int ''size'' = -1 )  <tt> [static]</tt>===

Returns a copy of the ''string'' string encoded in ucs4.

If ''size'' is -1 (the default), the ''string'' has to be 0 terminated.

This function was introduced in Qt 4.2.

See also [[Qt:Документация 4.3.2/qstring#fromUtf16 | fromUtf16]](), [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]](), [[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]](), [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]](), [[Qt:Документация 4.3.2/qstring#fromUcs4 | fromUcs4]](), and [[Qt:Документация 4.3.2/qstring#fromStdWString | fromStdWString]]().

===<div id="indexOf"></div>int QString::indexOf ( const QString &amp; ''str'', int ''from'' = 0, [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

Returns the index position of the first occurrence of the string ''str'' in this string, searching forward from index position ''from''. Returns -1 if ''str'' is not found.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]] (the default), the search is case sensitive; otherwise the search is case insensitive.

Example:
<source lang="cpp-qt">     QString x = "sticky question";
     QString y = "sti";
     x.indexOf(y);               // returns 0
     x.indexOf(y, 1);            // returns 10
     x.indexOf(y, 10);           // returns 10
     x.indexOf(y, 11);           // returns -1</source> 
If ''from'' is -1, the search starts at the last character; if it is -2, at the next to last character and so on.

See also [[Qt:Документация 4.3.2/qstring#lastIndexOf | lastIndexOf]](), [[Qt:Документация 4.3.2/qstring#contains | contains]](), and [[Qt:Документация 4.3.2/qstring#count | count]]().

===<div id="indexOf-2"></div>int QString::indexOf ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'', int ''from'' = 0, [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

This is an overloaded member function, provided for convenience.

Returns the index position of the first occurrence of the character ''ch'' in the string, searching forward from index position ''from''. Returns -1 if ''ch'' could not be found.

===<div id="indexOf-3"></div>int QString::indexOf ( const [[Qt:Документация 4.3.2/qregexp | QRegExp]] &amp; ''rx'', int ''from'' = 0 ) const===

This is an overloaded member function, provided for convenience.

Returns the index position of the first match of the regular expression ''rx'' in the string, searching forward from index position ''from''. Returns -1 if ''rx'' didn't match anywhere.

Example:
<source lang="cpp-qt">     QString str = "the minimum";
     str.indexOf(QRegExp("m[aeiou]"), 0);       // returns 4</source> 
===<div id="insert"></div>QString &amp; QString::insert ( int ''position'', const QString &amp; ''str'' )===

Inserts the string ''str'' at the given index ''position'' and returns a reference to this string.

Example:
<source lang="cpp-qt">     QString str = "Meal";
     str.insert(1, QString("ontr"));
     // str == "Montreal"</source> 
If the given ''position'' is greater than [[Qt:Документация 4.3.2/qstring#size | size]](), the array is first extended using [[Qt:Документация 4.3.2/qstring#resize | resize]]().

See also [[Qt:Документация 4.3.2/qstring#append | append]](), [[Qt:Документация 4.3.2/qstring#prepend | prepend]](), [[Qt:Документация 4.3.2/qstring#replace | replace]](), and [[Qt:Документация 4.3.2/qstring#remove | remove]]().

===<div id="insert-2"></div>QString &amp; QString::insert ( int ''position'', const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''str'' )===

This is an overloaded member function, provided for convenience.

Inserts the Latin-1 string ''str'' at the given index ''position''.

===<div id="insert-3"></div>QString &amp; QString::insert ( int ''position'', const [[Qt:Документация 4.3.2/qchar | QChar]] * ''unicode'', int ''size'' )===

This is an overloaded member function, provided for convenience.

Inserts the first ''size'' characters of the [[Qt:Документация 4.3.2/qchar | QChar]] array ''unicode'' at the given index ''position'' in the string.

===<div id="insert-4"></div>QString &amp; QString::insert ( int ''position'', [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'' )===

This is an overloaded member function, provided for convenience.

Inserts ''ch'' at the given index ''position'' in the string.

===<div id="isEmpty"></div>bool QString::isEmpty () const===

Returns true if the string has no characters; otherwise returns false.

Example:
<source lang="cpp-qt">     QString().isEmpty();            // returns true
     QString("").isEmpty();          // returns true
     QString("x").isEmpty();         // returns false
     QString("abc").isEmpty();       // returns false</source> 
See also [[Qt:Документация 4.3.2/qstring#size | size]]().

===<div id="isNull"></div>bool QString::isNull () const===

Returns true if this string is null; otherwise returns false.

Example:
<source lang="cpp-qt">     QString().isNull();             // returns true
     QString("").isNull();           // returns false
     QString("abc").isNull();        // returns false</source> 
Qt makes a distinction between null strings and empty strings for historical reasons. For most applications, what matters is whether or not a string contains any data, and this can be determined using the [[Qt:Документация 4.3.2/qstring#isEmpty | isEmpty]]() function.

See also [[Qt:Документация 4.3.2/qstring#isEmpty | isEmpty]]().

===<div id="lastIndexOf"></div>int QString::lastIndexOf ( const QString &amp; ''str'', int ''from'' = -1, [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

Returns the index position of the last occurrence of the string ''str'' in this string, searching backward from index position ''from''. If ''from'' is -1 (the default), the search starts at the last character; if ''from'' is -2, at the next to last character and so on. Returns -1 if ''str'' is not found.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]] (the default), the search is case sensitive; otherwise the search is case insensitive.

Example:
<source lang="cpp-qt">     QString x = "crazy azimuths";
     QString y = "az";
     x.lastIndexOf(y);           // returns 6
     x.lastIndexOf(y, 6);        // returns 6
     x.lastIndexOf(y, 5);        // returns 2
     x.lastIndexOf(y, 1);        // returns -1</source> 
See also [[Qt:Документация 4.3.2/qstring#indexOf | indexOf]](), [[Qt:Документация 4.3.2/qstring#contains | contains]](), and [[Qt:Документация 4.3.2/qstring#count | count]]().

===<div id="lastIndexOf-2"></div>int QString::lastIndexOf ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'', int ''from'' = -1, [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

This is an overloaded member function, provided for convenience.

Returns the index position of the last occurrence of the character ''ch'', searching backward from position ''from''.

===<div id="lastIndexOf-3"></div>int QString::lastIndexOf ( const [[Qt:Документация 4.3.2/qregexp | QRegExp]] &amp; ''rx'', int ''from'' = -1 ) const===

This is an overloaded member function, provided for convenience.

Returns the index position of the last match of the regular expression ''rx'' in the string, searching backward from index position ''from''. Returns -1 if ''rx'' didn't match anywhere.

Example:
<source lang="cpp-qt">     QString str = "the minimum";
     str.lastIndexOf(QRegExp("m[aeiou]"));      // returns 8</source> 
===<div id="left"></div>QString QString::left ( int ''n'' ) const===

Returns a substring that contains the ''n'' leftmost characters of the string.

The entire string is returned if ''n'' is greater than [[Qt:Документация 4.3.2/qstring#size | size]]() or less than zero.
<source lang="cpp-qt">     QString x = "Pineapple";
     QString y = x.left(4);      // y == "Pine"</source> 
See also [[Qt:Документация 4.3.2/qstring#right | right]](), [[Qt:Документация 4.3.2/qstring#mid | mid]](), and [[Qt:Документация 4.3.2/qstring#startsWith | startsWith]]().

===<div id="leftJustified"></div>QString QString::leftJustified ( int ''width'', [[Qt:Документация 4.3.2/qchar | QChar]] ''fill'' = QLatin1Char( ' ' ), bool ''truncate'' = false ) const===

Returns a string of size ''width'' that contains this string padded by the ''fill'' character.

If ''truncate'' is false and the [[Qt:Документация 4.3.2/qstring#size | size]]() of the string is more than ''width'', then the returned string is a copy of the string.
<source lang="cpp-qt">     QString s = "apple";
     QString t = s.leftJustified(8, '.');    // t == "apple..."</source> 
If ''truncate'' is true and the [[Qt:Документация 4.3.2/qstring#size | size]]() of the string is more than ''width'', then any characters in a copy of the string after position ''width'' are removed, and the copy is returned.
<source lang="cpp-qt">     QString str = "Pineapple";
     str = str.leftJustified(5, '.', true);    // str == "Pinea"</source> 
See also [[Qt:Документация 4.3.2/qstring#rightJustified | rightJustified]]().

===<div id="length"></div>int QString::length () const===

Returns the number of characters in this string. Equivalent to [[Qt:Документация 4.3.2/qstring#size | size]]().

See also [[Qt:Документация 4.3.2/qstring-qt3#setLength | setLength]]().

===<div id="localeAwareCompare"></div>int QString::localeAwareCompare ( const QString &amp; ''s1'', const QString &amp; ''s2'' )  <tt> [static]</tt>===

Compares ''s1'' with ''s2'' and returns an integer less than, equal to, or greater than zero if ''s1'' is less than, equal to, or greater than ''s2''.

The comparison is performed in a locale- and also platform-dependent manner. Use this function to present sorted lists of strings to the user.

On Mac OS X since Qt 4.3, this function compares according the "Order for sorted lists" setting in the International prefereces panel.

See also [[Qt:Документация 4.3.2/qstring#compare | compare]]() and [[Qt:Документация 4.3.2/qtextcodec-qt3#locale | QTextCodec::locale]]().

===<div id="localeAwareCompare-2"></div>int QString::localeAwareCompare ( const QString &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

Compares this string with the ''other'' string and returns an integer less than, equal to, or greater than zero if this string is less than, equal to, or greater than the ''other'' string.

Same as <tt>localeAwareCompare(*this, other)</tt>.

===<div id="mid"></div>QString QString::mid ( int ''position'', int ''n'' = -1 ) const===

Returns a string that contains ''n'' characters of this string, starting at the specified ''position'' index.

Returns an empty string if the ''position'' index exceeds the length of the string. If there are less than ''n'' characters available in the string starting at the given ''position'', or if ''n'' is -1 (the default), the function returns all characters that are available from the specified ''position''.

Example:
<source lang="cpp-qt">     QString x = "Nine pineapples";
     QString y = x.mid(5, 4);            // y == "pine"
     QString z = x.mid(5);               // z == "pineapples"</source> 
See also [[Qt:Документация 4.3.2/qstring#left | left]]() and [[Qt:Документация 4.3.2/qstring#right | right]]().

===<div id="normalized"></div>QString QString::normalized ( [[Qt:Документация 4.3.2/qstring#NormalizationForm-enum | NormalizationForm]] ''mode'' ) const===

Returns the string in the given Unicode normalization ''mode''.

===<div id="normalized-2"></div>QString QString::normalized ( [[Qt:Документация 4.3.2/qstring#NormalizationForm-enum | NormalizationForm]] ''mode'', [[Qt:Документация 4.3.2/qchar#UnicodeVersion-enum | QChar::UnicodeVersion]] ''version'' ) const===

This is an overloaded member function, provided for convenience.

Returns the string in the given Unicode normalization ''mode'', according to the given ''version'' of the Unicode standard.

===<div id="number"></div>QString QString::number ( long ''n'', int ''base'' = 10 )  <tt> [static]</tt>===

Returns a string equivalent of the number ''n'' according to the specified ''base''.

The base is 10 by default and must be between 2 and 36. For bases other than 10, ''n'' is treated as an unsigned integer.
<source lang="cpp-qt">     long a = 63;
     QString s = QString::number(a, 16);             // s == "3f"
     QString t = QString::number(a, 16).toUpper();     // t == "3F"</source> 
See also [[Qt:Документация 4.3.2/qstring#setNum | setNum]]().

===<div id="number-2"></div>QString QString::number ( [[Qt:Документация 4.3.2/qtglobal#ulong-typedef | ulong]] ''n'', int ''base'' = 10 )  <tt> [static]</tt>===

This is an overloaded member function, provided for convenience.

===<div id="number-3"></div>QString QString::number ( int ''n'', int ''base'' = 10 )  <tt> [static]</tt>===

This is an overloaded member function, provided for convenience.

===<div id="number-4"></div>QString QString::number ( [[Qt:Документация 4.3.2/qtglobal#uint-typedef | uint]] ''n'', int ''base'' = 10 )  <tt> [static]</tt>===

This is an overloaded member function, provided for convenience.

===<div id="number-5"></div>QString QString::number ( [[Qt:Документация 4.3.2/qtglobal#qlonglong-typedef | qlonglong]] ''n'', int ''base'' = 10 )  <tt> [static]</tt>===

This is an overloaded member function, provided for convenience.

===<div id="number-6"></div>QString QString::number ( [[Qt:Документация 4.3.2/qtglobal#qulonglong-typedef | qulonglong]] ''n'', int ''base'' = 10 )  <tt> [static]</tt>===

This is an overloaded member function, provided for convenience.

===<div id="number-7"></div>QString QString::number ( double ''n'', char ''format'' = 'g', int ''precision'' = 6 )  <tt> [static]</tt>===

This is an overloaded member function, provided for convenience.

Returns a string equivalent of the number ''n'', formatted according to the specified ''format'' and ''precision''. The ''format'' can be 'f', 'F', 'e', 'E', 'g' or 'G' (see the [[Qt:Документация 4.3.2/qstring#arg | arg]]() function documentation for an explanation of the formats).

Unlike [[Qt:Документация 4.3.2/qlocale#toString | QLocale::toString]](), this function does not honor the user's locale settings.

See also [[Qt:Документация 4.3.2/qstring#setNum | setNum]]() and [[Qt:Документация 4.3.2/qlocale#toString | QLocale::toString]]().

===<div id="prepend"></div>QString &amp; QString::prepend ( const QString &amp; ''str'' )===

Prepends the string ''str'' to the beginning of this string and returns a reference to this string.

Example:
<source lang="cpp-qt">     QString x = "ship";
     QString y = "air";
     x.prepend(y);
     // x == "airship"</source> 
See also [[Qt:Документация 4.3.2/qstring#append | append]]() and [[Qt:Документация 4.3.2/qstring#insert | insert]]().

===<div id="prepend-2"></div>QString &amp; QString::prepend ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''str'' )===

This is an overloaded member function, provided for convenience.

Prepends the Latin-1 string ''str'' to this string.

===<div id="prepend-3"></div>QString &amp; QString::prepend ( const [[Qt:Документация 4.3.2/qbytearray | QByteArray]] &amp; ''ba'' )===

This is an overloaded member function, provided for convenience.

Prepends the byte array ''ba'' to this string. The byte array is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this function by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="prepend-4"></div>QString &amp; QString::prepend ( const char * ''str'' )===

This is an overloaded member function, provided for convenience.

Prepends the string ''str'' to this string. The const char pointer is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this function by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="prepend-5"></div>QString &amp; QString::prepend ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'' )===

This is an overloaded member function, provided for convenience.

Prepends the character ''ch'' to this string.

===<div id="push_back"></div>void QString::push_back ( const QString &amp; ''other'' )===

This function is provided for STL compatibility, appending the given ''other'' string onto the end of this string. It is equivalent to <tt>append(other)</tt>.

See also [[Qt:Документация 4.3.2/qstring#append | append]]().

===<div id="push_back-2"></div>void QString::push_back ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'' )===

This is an overloaded member function, provided for convenience.

Appends the given ''ch'' character onto the end of this string.

===<div id="push_front"></div>void QString::push_front ( const QString &amp; ''other'' )===

This function is provided for STL compatibility, prepending the given ''other'' string to the beginning of this string. It is equivalent to <tt>prepend(other)</tt>.

See also [[Qt:Документация 4.3.2/qstring#prepend | prepend]]().

===<div id="push_front-2"></div>void QString::push_front ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'' )===

This is an overloaded member function, provided for convenience.

Prepends the given ''ch'' character to the beginning of this string.

===<div id="remove"></div>QString &amp; QString::remove ( int ''position'', int ''n'' )===

Removes ''n'' characters from the string, starting at the given ''position'' index, and returns a reference to the string.

If the specified ''position'' index is within the string, but ''position'' + ''n'' is beyond the end of the string, the string is truncated at the specified ''position''.
<source lang="cpp-qt">     QString s = "Montreal";
     s.remove(1, 4);
     // s == "Meal"</source> 
See also [[Qt:Документация 4.3.2/qstring#insert | insert]]() and [[Qt:Документация 4.3.2/qstring#replace | replace]]().

===<div id="remove-4"></div>QString &amp; QString::remove ( const QString &amp; ''str'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive )===

This is an overloaded member function, provided for convenience.

Removes every occurrence of the given ''str'' string in this string, and returns a reference to this string.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]] (the default), the search is case sensitive; otherwise the search is case insensitive.

This is the same as <tt>replace(str, "", cs)</tt>.

See also [[Qt:Документация 4.3.2/qstring#replace | replace]]().

===<div id="remove-5"></div>QString &amp; QString::remove ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive )===

This is an overloaded member function, provided for convenience.

Removes every occurrence of the character ''ch'' in this string, and returns a reference to this string.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]] (the default), the search is case sensitive; otherwise the search is case insensitive.

Example:
<source lang="cpp-qt">     QString t = "Ali Baba";
     t.remove(QChar('a'), Qt::CaseInsensitive);
     // t == "li Bb"</source> 
This is the same as <tt>replace(ch, "", cs)</tt>.

See also [[Qt:Документация 4.3.2/qstring#replace | replace]]().

===<div id="remove-6"></div>QString &amp; QString::remove ( const [[Qt:Документация 4.3.2/qregexp | QRegExp]] &amp; ''rx'' )===

This is an overloaded member function, provided for convenience.

Removes every occurrence of the regular expression ''rx'' in the string, and returns a reference to the string. For example:
<source lang="cpp-qt">     QString r = "Telephone";
     r.remove(QRegExp("[aeiou]."));
     // r == "The"</source> 
See also [[Qt:Документация 4.3.2/qstring#indexOf | indexOf]](), [[Qt:Документация 4.3.2/qstring#lastIndexOf | lastIndexOf]](), and [[Qt:Документация 4.3.2/qstring#replace | replace]]().

===<div id="replace"></div>QString &amp; QString::replace ( int ''position'', int ''n'', const QString &amp; ''after'' )===

Replaces ''n'' characters from the specified index ''position'' with the string ''after'', and returns a reference to this string.

Example:
<source lang="cpp-qt">     QString x = "Say yes!";
     QString y = "no";
     x.replace(4, 3, y);
     // x == "Say no!"</source> 
See also [[Qt:Документация 4.3.2/qstring#insert | insert]]() and [[Qt:Документация 4.3.2/qstring#remove | remove]]().

===<div id="replace-6"></div>QString &amp; QString::replace ( int ''position'', int ''n'', const [[Qt:Документация 4.3.2/qchar | QChar]] * ''unicode'', int ''size'' )===

This is an overloaded member function, provided for convenience.

Replaces ''n'' characters from the specified index ''position'' with the first ''size'' characters of the [[Qt:Документация 4.3.2/qchar | QChar]] array ''unicode''.

===<div id="replace-7"></div>QString &amp; QString::replace ( int ''position'', int ''n'', [[Qt:Документация 4.3.2/qchar | QChar]] ''after'' )===

This is an overloaded member function, provided for convenience.

Replaces ''n'' characters from the specified index ''position'' with the character ''after''.

===<div id="replace-8"></div>QString &amp; QString::replace ( const QString &amp; ''before'', const QString &amp; ''after'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive )===

This is an overloaded member function, provided for convenience.

Replaces every occurrence of the string ''before'' with the string ''after''.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]] (the default), the search is case sensitive; otherwise the search is case insensitive.

Example:
<source lang="cpp-qt">     QString str = "colour behaviour flavour neighbour";
     str.replace(QString("ou"), QString("o"));
     // str == "color behavior flavor neighbor"</source> 
===<div id="replace-9"></div>QString &amp; QString::replace ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'', const QString &amp; ''after'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive )===

This is an overloaded member function, provided for convenience.

Replaces every occurrence of the character ''ch'' in the string with ''after''. Returns a reference to the string.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]] (the default), the search is case sensitive; otherwise the search is case insensitive.

===<div id="replace-10"></div>QString &amp; QString::replace ( [[Qt:Документация 4.3.2/qchar | QChar]] ''before'', [[Qt:Документация 4.3.2/qchar | QChar]] ''after'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive )===

This is an overloaded member function, provided for convenience.

Replaces every occurrence of the character ''before'' with the character ''after''. Returns a reference to the string.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]] (the default), the search is case sensitive; otherwise the search is case insensitive.

===<div id="replace-11"></div>QString &amp; QString::replace ( const [[Qt:Документация 4.3.2/qregexp | QRegExp]] &amp; ''rx'', const QString &amp; ''after'' )===

This is an overloaded member function, provided for convenience.

Replaces every occurrence of the regular expression ''rx'' in the string with ''after''. Returns a reference to the string. For example:
<source lang="cpp-qt">     QString s = "Banana";
     s.replace(QRegExp("a[mn]"), "ox");
     // s == "Boxoxa"</source> 
For regular expressions containing [[Qt:Документация 4.3.2/qregexp#capturing-parentheses | capturing parentheses]], occurrences of '''\1''', '''\2''', ..&#x2e;, in ''after'' are replaced with ''rx''.cap(1), cap(2), ..&#x2e;
<source lang="cpp-qt">     QString t = "A <i>bon mot</i>.";
     t.replace(QRegExp("<i>([^<]*)</i>"), "\\emph{\\1}");
     // t == "A \\emph{bon mot}."</source> 
See also [[Qt:Документация 4.3.2/qstring#indexOf | indexOf]](), [[Qt:Документация 4.3.2/qstring#lastIndexOf | lastIndexOf]](), [[Qt:Документация 4.3.2/qstring#remove | remove]](), and [[Qt:Документация 4.3.2/qregexp#cap | QRegExp::cap]]().

===<div id="reserve"></div>void QString::reserve ( int ''size'' )===

Attempts to allocate memory for at least ''size'' characters. If you know in advance how large the string will be, you can call this function, and if you resize the string often you are likely to get better performance. If ''size'' is an underestimate, the worst that will happen is that the [[Qt:Документация 4.3.2/qstring | QString]] will be a bit slower.

The sole purpose of this function is to provide a means of fine tuning [[Qt:Документация 4.3.2/qstring | QString]]'s memory usage. In general, you will rarely ever need to call this function. If you want to change the size of the string, call [[Qt:Документация 4.3.2/qstring#resize | resize]]().

This function is useful for code that needs to build up a long string and wants to avoid repeated reallocation. In this example, we want to add to the string until some condition is true, and we're fairly sure that size is large enough to make a call to reserve() worthwhile:
<source lang="cpp-qt">     QString result;
     int maxSize;
     bool condition;
     QChar nextChar;

     result.reserve(maxSize);

     while (condition)
         result.append(nextChar);

     result.squeeze();</source> 
See also [[Qt:Документация 4.3.2/qstring#squeeze | squeeze]]() and [[Qt:Документация 4.3.2/qstring#capacity | capacity]]().

===<div id="resize"></div>void QString::resize ( int ''size'' )===

Sets the size of the string to ''size'' characters.

If ''size'' is greater than the current size, the string is extended to make it ''size'' characters long with the extra characters added to the end. The new characters are uninitialized.

If ''size'' is less than the current size, characters are removed from the end.

Example:
<source lang="cpp-qt">     QString s = "Hello world";
     s.resize(5);
     // s == "Hello"

     s.resize(8);
     // s == "Hello???" (where ? stands for any character)</source> 
If you want to append a certain number of identical characters to the string, use [[Qt:Документация 4.3.2/qstring#operator-2b-eq | operator+=]]() as follows rather than resize():
<source lang="cpp-qt">     QString t = "Hello";
     t += QString(10, 'X');
     // t == "HelloXXXXXXXXXX"</source> 
If you want to expand the string so that it reaches a certain width and fill the new positions with a particular character, use the [[Qt:Документация 4.3.2/qstring#leftJustified | leftJustified]]() function:
<source lang="cpp-qt">     QString r = "Hello";
     r = r.leftJustified(10, ' ');
     // r == "Hello     "</source> 
See also [[Qt:Документация 4.3.2/qstring#truncate | truncate]]() and [[Qt:Документация 4.3.2/qstring#reserve | reserve]]().

===<div id="right"></div>QString QString::right ( int ''n'' ) const===

Returns a substring that contains the ''n'' rightmost characters of the string.

The entire string is returned if ''n'' is greater than [[Qt:Документация 4.3.2/qstring#size | size]]() or less than zero.
<source lang="cpp-qt">     QString x = "Pineapple";
     QString y = x.right(5);      // y == "apple"</source> 
See also [[Qt:Документация 4.3.2/qstring#left | left]](), [[Qt:Документация 4.3.2/qstring#mid | mid]](), and [[Qt:Документация 4.3.2/qstring#endsWith | endsWith]]().

===<div id="rightJustified"></div>QString QString::rightJustified ( int ''width'', [[Qt:Документация 4.3.2/qchar | QChar]] ''fill'' = QLatin1Char( ' ' ), bool ''truncate'' = false ) const===

Returns a string of [[Qt:Документация 4.3.2/qstring#size | size]]() ''width'' that contains the ''fill'' character followed by the string. For example:
<source lang="cpp-qt">     QString s = "apple";
     QString t = s.rightJustified(8, '.');    // t == "...apple"</source> 
If ''truncate'' is false and the [[Qt:Документация 4.3.2/qstring#size | size]]() of the string is more than ''width'', then the returned string is a copy of the string.

If ''truncate'' is true and the [[Qt:Документация 4.3.2/qstring#size | size]]() of the string is more than ''width'', then the resulting string is truncated at position ''width''.
<source lang="cpp-qt">     QString str = "Pineapple";
     str = str.rightJustified(5, '.', true);    // str == "Pinea"</source> 
See also [[Qt:Документация 4.3.2/qstring#leftJustified | leftJustified]]().

===<div id="section"></div>QString QString::section ( [[Qt:Документация 4.3.2/qchar | QChar]] ''sep'', int ''start'', int ''end'' = -1, [[Qt:Документация 4.3.2/qstring#SectionFlag-enum | SectionFlags]] ''flags'' = SectionDefault ) const===

This function returns a section of the string.

This string is treated as a sequence of fields separated by the character, ''sep''. The returned string consists of the fields from position ''start'' to position ''end'' inclusive. If ''end'' is not specified, all fields from position ''start'' to the end of the string are included. Fields are numbered 0, 1, 2, etc., counting from the left, and -1, -2, etc., counting from right to left.

The ''flags'' argument can be used to affect some aspects of the function's behavior, e.g&#x2e; whether to be case sensitive, whether to skip empty fields and how to deal with leading and trailing separators; see [[Qt:Документация 4.3.2/qstring#SectionFlag-enum | SectionFlags]].
<source lang="cpp-qt">     QString str;
     QString csv = "forename,middlename,surname,phone";
     QString path = "/usr/local/bin/myapp"; // First field is empty
     QString::SectionFlag flag = QString::SectionSkipEmpty;

     str = csv.section(',', 2, 2);   // str == "surname"
     str = path.section('/', 3, 4);  // str == "bin/myapp"
     str = path.section('/', 3, 3, flag); // str == "myapp"</source> 
If ''start'' or ''end'' is negative, we count fields from the right of the string, the right-most field being -1, the one from right-most field being -2, and so on.
<source lang="cpp-qt">     str = csv.section(',', -3, -2);  // str == "middlename,surname"
     str = path.section('/', -1); // str == "myapp"</source> 
See also [[Qt:Документация 4.3.2/qstring#split | split]]().

===<div id="section-2"></div>QString QString::section ( const QString &amp; ''sep'', int ''start'', int ''end'' = -1, [[Qt:Документация 4.3.2/qstring#SectionFlag-enum | SectionFlags]] ''flags'' = SectionDefault ) const===

This is an overloaded member function, provided for convenience.
<source lang="cpp-qt">     QString str;
     QString data = "forename**middlename**surname**phone";

     str = data.section("**", 2, 2); // str == "surname"
     str = data.section("**", -3, -2); // str == "middlename**surname"</source> 
See also [[Qt:Документация 4.3.2/qstring#split | split]]().

===<div id="section-3"></div>QString QString::section ( const [[Qt:Документация 4.3.2/qregexp | QRegExp]] &amp; ''reg'', int ''start'', int ''end'' = -1, [[Qt:Документация 4.3.2/qstring#SectionFlag-enum | SectionFlags]] ''flags'' = SectionDefault ) const===

This is an overloaded member function, provided for convenience.

This string is treated as a sequence of fields separated by the regular expression, ''reg''.
<source lang="cpp-qt">     QString line = "forename\tmiddlename  surname \t \t phone";
     QRegExp sep("\\s+");
     str = line.section(sep, 2, 2); // s == "surname"
     str = line.section(sep, -3, -2); // s == "middlename  surname"</source> 
'''Warning:''' Using this [[Qt:Документация 4.3.2/qregexp | QRegExp]] version is much more expensive than the overloaded string and character versions.

See also [[Qt:Документация 4.3.2/qstring#split | split]]() and [[Qt:Документация 4.3.2/qstring#simplified | simplified]]().

===<div id="setNum"></div>QString &amp; QString::setNum ( int ''n'', int ''base'' = 10 )===

Sets the string to the printed value of ''n'' in the specified ''base'', and returns a reference to the string.

The base is 10 by default and must be between 2 and 36. For bases other than 10, ''n'' is treated as an unsigned integer.
<source lang="cpp-qt">     QString str;
     str.setNum(1234);       // str == "1234"</source> 
===<div id="setNum-2"></div>QString &amp; QString::setNum ( [[Qt:Документация 4.3.2/qtglobal#uint-typedef | uint]] ''n'', int ''base'' = 10 )===

This is an overloaded member function, provided for convenience.

===<div id="setNum-3"></div>QString &amp; QString::setNum ( long ''n'', int ''base'' = 10 )===

This is an overloaded member function, provided for convenience.

===<div id="setNum-4"></div>QString &amp; QString::setNum ( [[Qt:Документация 4.3.2/qtglobal#ulong-typedef | ulong]] ''n'', int ''base'' = 10 )===

This is an overloaded member function, provided for convenience.

===<div id="setNum-5"></div>QString &amp; QString::setNum ( [[Qt:Документация 4.3.2/qtglobal#qlonglong-typedef | qlonglong]] ''n'', int ''base'' = 10 )===

This is an overloaded member function, provided for convenience.

===<div id="setNum-6"></div>QString &amp; QString::setNum ( [[Qt:Документация 4.3.2/qtglobal#qulonglong-typedef | qulonglong]] ''n'', int ''base'' = 10 )===

This is an overloaded member function, provided for convenience.

===<div id="setNum-7"></div>QString &amp; QString::setNum ( short ''n'', int ''base'' = 10 )===

This is an overloaded member function, provided for convenience.

===<div id="setNum-8"></div>QString &amp; QString::setNum ( [[Qt:Документация 4.3.2/qtglobal#ushort-typedef | ushort]] ''n'', int ''base'' = 10 )===

This is an overloaded member function, provided for convenience.

===<div id="setNum-9"></div>QString &amp; QString::setNum ( double ''n'', char ''format'' = 'g', int ''precision'' = 6 )===

This is an overloaded member function, provided for convenience.

Sets the string to the printed value of ''n'', formatted according to the given ''format'' and ''precision'', and returns a reference to the string.

The ''format'' can be 'f', 'F', 'e', 'E', 'g' or 'G' (see the [[Qt:Документация 4.3.2/qstring#arg | arg]]() function documentation for an explanation of the formats).

Unlike [[Qt:Документация 4.3.2/qlocale#toString | QLocale::toString]](), this function doesn't honor the user's locale settings.

===<div id="setNum-10"></div>QString &amp; QString::setNum ( float ''n'', char ''format'' = 'g', int ''precision'' = 6 )===

This is an overloaded member function, provided for convenience.

Sets the string to the printed value of ''n'', formatted according to the given ''format'' and ''precision'', and returns a reference to the string.

===<div id="setUnicode"></div>QString &amp; QString::setUnicode ( const [[Qt:Документация 4.3.2/qchar | QChar]] * ''unicode'', int ''size'' )===

Resizes the string to ''size'' characters and copies ''unicode'' into the string.

If ''unicode'' is 0, nothing is copied, but the string is still resized to ''size''.

See also [[Qt:Документация 4.3.2/qstring#unicode | unicode]]() and [[Qt:Документация 4.3.2/qstring#setUtf16 | setUtf16]]().

===<div id="setUtf16"></div>QString &amp; QString::setUtf16 ( const [[Qt:Документация 4.3.2/qtglobal#ushort-typedef | ushort]] * ''unicode'', int ''size'' )===

Resizes the string to ''size'' characters and copies ''unicode'' into the string.

If ''unicode'' is 0, nothing is copied, but the string is still resized to ''size''.

See also [[Qt:Документация 4.3.2/qstring#utf16 | utf16]]() and [[Qt:Документация 4.3.2/qstring#setUnicode | setUnicode]]().

===<div id="simplified"></div>QString QString::simplified () const===

Returns a string that has whitespace removed from the start and the end, and that has each sequence of internal whitespace replaced with a single space.

Whitespace means any character for which [[Qt:Документация 4.3.2/qchar#isSpace | QChar::isSpace]]() returns true. This includes the ASCII characters '\t', '\n', '\v', '\f', '\r', and ' '.

Example:
<source lang="cpp-qt">     QString str = "  lots\t of\nwhitespace\r\n ";
     str = str.simplified();
     // str == "lots of whitespace";</source> 
See also [[Qt:Документация 4.3.2/qstring#trimmed | trimmed]]().

===<div id="size"></div>int QString::size () const===

Returns the number of characters in this string.

The last character in the string is at position size() - 1. In addition, [[Qt:Документация 4.3.2/qstring | QString]] ensures that the character at position size() is always '\0', so that you can use the return value of [[Qt:Документация 4.3.2/qstring#data | data]]() and [[Qt:Документация 4.3.2/qstring#constData | constData]]() as arguments to functions that expect '\0'-terminated strings.

Example:
<source lang="cpp-qt">     QString str = "World";
     int n = str.size();         // n == 5
     str.data()[0];              // returns 'W'
     str.data()[4];              // returns 'd'
     str.data()[5];              // returns '\0'</source> 
See also [[Qt:Документация 4.3.2/qstring#isEmpty | isEmpty]]() and [[Qt:Документация 4.3.2/qstring#resize | resize]]().

===<div id="split"></div>[[Qt:Документация 4.3.2/qstringlist | QStringList]] QString::split ( const QString &amp; ''sep'', [[Qt:Документация 4.3.2/qstring#SplitBehavior-enum | SplitBehavior]] ''behavior'' = KeepEmptyParts, [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

Splits the string into substrings wherever ''sep'' occurs, and returns the list of those strings. If ''sep'' does not match anywhere in the string, split() returns a single-element list containing this string.

''cs'' specifies whether ''sep'' should be matched case sensitively or case insensitively.

If ''behavior'' is [[Qt:Документация 4.3.2/qstring#SplitBehavior-enum | QString::SkipEmptyParts]], empty entries don't appear in the result. By default, empty entries are kept.

Example:
<source lang="cpp-qt">     QString str = "a,,b,c";

     QStringList list1 = str.split(",");
     // list1: [ "a", "", "b", "c" ]

     QStringList list2 = str.split(",", QString::SkipEmptyParts);
     // list2: [ "a", "b", "c" ]</source> 
See also [[Qt:Документация 4.3.2/qstringlist#join | QStringList::join]]() and [[Qt:Документация 4.3.2/qstring#section | section]]().

===<div id="split-2"></div>[[Qt:Документация 4.3.2/qstringlist | QStringList]] QString::split ( const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''sep'', [[Qt:Документация 4.3.2/qstring#SplitBehavior-enum | SplitBehavior]] ''behavior'' = KeepEmptyParts, [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

This is an overloaded member function, provided for convenience.

===<div id="split-3"></div>[[Qt:Документация 4.3.2/qstringlist | QStringList]] QString::split ( const [[Qt:Документация 4.3.2/qregexp | QRegExp]] &amp; ''rx'', [[Qt:Документация 4.3.2/qstring#SplitBehavior-enum | SplitBehavior]] ''behavior'' = KeepEmptyParts ) const===

This is an overloaded member function, provided for convenience.

Splits the string into substrings wherever the regular expression ''rx'' matches, and returns the list of those strings. If ''rx'' does not match anywhere in the string, [[Qt:Документация 4.3.2/qstring#split | split]]() returns a single-element list containing this string.

Here's an example where we extract the words in a sentence using one or more whitespace characters as the separator:
<source lang="cpp-qt">     QString str;
     QStringList list;

     str = "Some  text\n\twith  strange whitespace.";
     list = str.split(QRegExp("\\s+"));
     // list: [ "Some", "text", "with", "strange", "whitespace." ]</source> 
Here's a similar example, but this time we use any sequence of non-word characters as the separator:
<source lang="cpp-qt">     str = "This time, a normal English sentence.";
     list = str.split(QRegExp("\\W+"), QString::SkipEmptyParts);
     // list: [ "This", "time", "a", "normal", "English", "sentence" ]</source> 
Here's a third example where we use a zero-length assertion, '''\b''' (word boundary), to split the string into an alternating sequence of non-word and word tokens:
<source lang="cpp-qt">     str = "Now: this sentence fragment.";
     list = str.split(QRegExp("\\b"));
     // list: [ "", "Now", ": ", "this", " ", "sentence", " ", "fragment", "." ]</source> 
See also [[Qt:Документация 4.3.2/qstringlist#join | QStringList::join]]() and [[Qt:Документация 4.3.2/qstring#section | section]]().

===<div id="sprintf"></div>QString &amp; QString::sprintf ( const char * ''cformat'', ... )===

Safely builds a formatted string from the format string ''cformat'' and an arbitrary list of arguments.

The %lc escape sequence expects a unicode character of type ushort (as returned by [[Qt:Документация 4.3.2/qchar#unicode | QChar::unicode]]()). The %ls escape sequence expects a pointer to a zero-terminated array of unicode characters of type ushort (as returned by [[Qt:Документация 4.3.2/qstring#utf16 | QString::utf16]]()).

The format string supports most of the conversion specifiers provided by printf() in the standard C++ library. It doesn't honor the length modifiers (e.g&#x2e; <tt>h</tt> for <tt>short</tt>, <tt>ll</tt> for <tt>long long</tt>). If you need those, use the standard snprintf() function instead:
<source lang="cpp-qt">     size_t BufSize;
     char buf[BufSize];

     ::snprintf(buf, BufSize, "%lld", 123456789LL);
     QString str = QString::fromAscii(buf);</source> 
'''Warning:''' We do not recommend using QString::sprintf() in new Qt code. Instead, consider using [[Qt:Документация 4.3.2/qtextstream | QTextStream]] or [[Qt:Документация 4.3.2/qstring#arg | arg]](), both of which support Unicode strings seamlessly and are type-safe. Here's an example that uses [[Qt:Документация 4.3.2/qtextstream | QTextStream]]:
<source lang="cpp-qt">     QString result;
     QTextStream(&amp;result) << "pi = " << 3.14;
     // result == "pi = 3.14"</source> 
For [[Qt:Документация 4.3.2/qobject#tr | translations]], especially if the strings contains more than one escape sequence, you should consider using the [[Qt:Документация 4.3.2/qstring#arg | arg]]() function instead. This allows the order of the replacements to be controlled by the translator.

See also [[Qt:Документация 4.3.2/qstring#arg | arg]]().

===<div id="squeeze"></div>void QString::squeeze ()===

Releases any memory not required to store the character data.

The sole purpose of this function is to provide a means of fine tuning [[Qt:Документация 4.3.2/qstring | QString]]'s memory usage. In general, you will rarely ever need to call this function.

See also [[Qt:Документация 4.3.2/qstring#reserve | reserve]]() and [[Qt:Документация 4.3.2/qstring#capacity | capacity]]().

===<div id="startsWith"></div>bool QString::startsWith ( const QString &amp; ''s'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

Returns true if the string starts with ''s''; otherwise returns false.

If ''cs'' is [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitive]] (the default), the search is case sensitive; otherwise the search is case insensitive.
<source lang="cpp-qt">     QString str = "Bananas";
     str.startsWith("Ban");     // returns true
     str.startsWith("Car");     // returns false</source> 
See also [[Qt:Документация 4.3.2/qstring#endsWith | endsWith]]().

===<div id="startsWith-3"></div>bool QString::startsWith ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''s'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

This is an overloaded member function, provided for convenience.

===<div id="startsWith-4"></div>bool QString::startsWith ( const [[Qt:Документация 4.3.2/qchar | QChar]] &amp; ''c'', [[Qt:Документация 4.3.2/qt#CaseSensitivity-enum | Qt::CaseSensitivity]] ''cs'' = Qt::CaseSensitive ) const===

This is an overloaded member function, provided for convenience.

Returns true if the string starts with ''c''; otherwise returns false.

===<div id="toAscii"></div>[[Qt:Документация 4.3.2/qbytearray | QByteArray]] QString::toAscii () const===

Returns an 8-bit ASCII representation of the string as a [[Qt:Документация 4.3.2/qbytearray | QByteArray]].

If a codec has been set using [[Qt:Документация 4.3.2/qtextcodec#setCodecForCStrings | QTextCodec::setCodecForCStrings]](), it is used to convert Unicode to 8-bit char; otherwise this function does the same as [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]]().

See also [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]](), [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]](), [[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]](), [[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]](), and [[Qt:Документация 4.3.2/qtextcodec | QTextCodec]].

===<div id="toCaseFolded"></div>QString QString::toCaseFolded () const===

Returns the case folded equivalent of the string. For most Unicode characters this is the same as toLowerCase().

===<div id="toDouble"></div>double QString::toDouble ( bool * ''ok'' = 0 ) const===

Returns the string converted to a <tt>double</tt> value.

Returns 0.0 if the conversion fails.

If a conversion error occurs, <tt>*</tt>''ok'' is set to false; otherwise <tt>*</tt>''ok'' is set to true.
<source lang="cpp-qt">     QString str = "1234.56";
     double val = str.toDouble();   // val == 1234.56</source> 
Various string formats for floating point numbers can be converted to double values:
<source lang="cpp-qt">     bool ok;
     double d;

     d = QString( "1234.56e-02" ).toDouble(&amp;ok); // ok == true, d == 12.3456</source> 
This function tries to interpret the string according to the current locale. The current locale is determined from the system at application startup and can be changed by calling [[Qt:Документация 4.3.2/qlocale#setDefault | QLocale::setDefault]](). If the string cannot be interpreted according to the current locale, this function falls back on the "C" locale.
<source lang="cpp-qt">     QLocale::setDefault(QLocale::C);
     d = QString( "1234,56" ).toDouble(&amp;ok); // ok == false
     d = QString( "1234.56" ).toDouble(&amp;ok); // ok == true, d == 1234.56

     QLocale::setDefault(QLocale::German);
     d = QString( "1234,56" ).toDouble(&amp;ok); // ok == true, d == 1234.56
     d = QString( "1234.56" ).toDouble(&amp;ok); // ok == true, d == 1234.56</source> 
Due to the ambiguity between the decimal point and thousands group separator in various locales, this function does not handle thousands group separators. If you need to convert such numbers, see [[Qt:Документация 4.3.2/qlocale#toDouble | QLocale::toDouble]]().
<source lang="cpp-qt">     QLocale::setDefault(QLocale::C);
     d = QString( "1234,56" ).toDouble(&amp;ok); // ok == false</source> 
See also [[Qt:Документация 4.3.2/qstring#number | number]](), [[Qt:Документация 4.3.2/qlocale#setDefault | QLocale::setDefault]](), [[Qt:Документация 4.3.2/qlocale#toDouble | QLocale::toDouble]](), and [[Qt:Документация 4.3.2/qstring#trimmed | trimmed]]().

===<div id="toFloat"></div>float QString::toFloat ( bool * ''ok'' = 0 ) const===

Returns the string converted to a <tt>float</tt> value.

If a conversion error occurs, *''ok'' is set to false; otherwise *''ok'' is set to true. Returns 0.0 if the conversion fails.

Example:
<source lang="cpp-qt">     QString str1 = "1234.56";
     str1.toFloat();             // returns 1234.56

     bool ok;
     QString str2 = "R2D2";
     str2.toFloat(&amp;ok);          // returns 0.0, sets ok to false</source> 
See also [[Qt:Документация 4.3.2/qstring#number | number]](), [[Qt:Документация 4.3.2/qstring#toDouble | toDouble]](), and [[Qt:Документация 4.3.2/qstring#toInt | toInt]]().

===<div id="toInt"></div>int QString::toInt ( bool * ''ok'' = 0, int ''base'' = 10 ) const===

Returns the string converted to an <tt>int</tt> using base ''base'', which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If a conversion error occurs, *''ok'' is set to false; otherwise *''ok'' is set to true.

If ''base'' is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

Example:
<source lang="cpp-qt">     QString str = "FF";
     bool ok;
     int hex = str.toInt(&amp;ok, 16);       // hex == 255, ok == true
     int dec = str.toInt(&amp;ok, 10);       // dec == 0, ok == false</source> 
See also [[Qt:Документация 4.3.2/qstring#number | number]](), [[Qt:Документация 4.3.2/qstring#toUInt | toUInt]](), and [[Qt:Документация 4.3.2/qstring#toDouble | toDouble]]().

===<div id="toLatin1"></div>[[Qt:Документация 4.3.2/qbytearray | QByteArray]] QString::toLatin1 () const===

Returns a Latin-1 representation of the string as a [[Qt:Документация 4.3.2/qbytearray | QByteArray]]. The returned byte array is undefined if the string contains non-Latin1 characters.

See also [[Qt:Документация 4.3.2/qstring#fromLatin1 | fromLatin1]](), [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]](), [[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]](), [[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]](), and [[Qt:Документация 4.3.2/qtextcodec | QTextCodec]].

===<div id="toLocal8Bit"></div>[[Qt:Документация 4.3.2/qbytearray | QByteArray]] QString::toLocal8Bit () const===

Returns the local 8-bit representation of the string as a [[Qt:Документация 4.3.2/qbytearray | QByteArray]]. The returned byte array is undefined if the string contains characters not supported by the local 8-bit encoding.

[[Qt:Документация 4.3.2/qtextcodec#codecForLocale | QTextCodec::codecForLocale]]() is used to perform the conversion from Unicode.

See also [[Qt:Документация 4.3.2/qstring#fromLocal8Bit | fromLocal8Bit]](), [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]](), [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]](), [[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]](), and [[Qt:Документация 4.3.2/qtextcodec | QTextCodec]].

===<div id="toLong"></div>long QString::toLong ( bool * ''ok'' = 0, int ''base'' = 10 ) const===

Returns the string converted to a <tt>long</tt> using base ''base'', which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If a conversion error occurs, *''ok'' is set to false; otherwise *''ok'' is set to true.

If ''base'' is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

Example:
<source lang="cpp-qt">     QString str = "FF";
     bool ok;

     long hex = str.toLong(&amp;ok, 16);     // hex == 255, ok == true
     long dec = str.toLong(&amp;ok, 10);     // dec == 0, ok == false</source> 
See also [[Qt:Документация 4.3.2/qstring#number | number]](), [[Qt:Документация 4.3.2/qstring#toULong | toULong]](), and [[Qt:Документация 4.3.2/qstring#toInt | toInt]]().

===<div id="toLongLong"></div>[[Qt:Документация 4.3.2/qtglobal#qlonglong-typedef | qlonglong]] QString::toLongLong ( bool * ''ok'' = 0, int ''base'' = 10 ) const===

Returns the string converted to a <tt>long long</tt> using base ''base'', which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If a conversion error occurs, *''ok'' is set to false; otherwise *''ok'' is set to true.

If ''base'' is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

Example:
<source lang="cpp-qt">     QString str = "FF";
     bool ok;

     qint64 hex = str.toLongLong(&amp;ok, 16);      // hex == 255, ok == true
     qint64 dec = str.toLongLong(&amp;ok, 10);      // dec == 0, ok == false</source> 
See also [[Qt:Документация 4.3.2/qstring#number | number]](), [[Qt:Документация 4.3.2/qstring#toULongLong | toULongLong]](), and [[Qt:Документация 4.3.2/qstring#toInt | toInt]]().

===<div id="toLower"></div>QString QString::toLower () const===

Returns a lowercase copy of the string.
<source lang="cpp-qt">     QString str = "TROlltECH";
     str = str.toLower();        // str == "trolltech"</source> 
See also [[Qt:Документация 4.3.2/qstring#toUpper | toUpper]]().

===<div id="toShort"></div>short QString::toShort ( bool * ''ok'' = 0, int ''base'' = 10 ) const===

Returns the string converted to a <tt>short</tt> using base ''base'', which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If a conversion error occurs, *''ok'' is set to false; otherwise *''ok'' is set to true.

If ''base'' is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

Example:
<source lang="cpp-qt">     QString str = "FF";
     bool ok;

     short hex = str.toShort(&amp;ok, 16);   // hex == 255, ok == true
     short dec = str.toShort(&amp;ok, 10);   // dec == 0, ok == false</source> 
See also [[Qt:Документация 4.3.2/qstring#number | number]](), [[Qt:Документация 4.3.2/qstring#toUShort | toUShort]](), and [[Qt:Документация 4.3.2/qstring#toInt | toInt]]().

===<div id="toStdString"></div>std::string QString::toStdString () const===

Returns a std::string object with the data contained in this [[Qt:Документация 4.3.2/qstring | QString]]. The Unicode data is converted into 8-bit characters using the [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]]() function.

This operator is mostly useful to pass a [[Qt:Документация 4.3.2/qstring | QString]] to a function that accepts a std::string object.

If the [[Qt:Документация 4.3.2/qstring | QString]] contains non-ASCII Unicode characters, using this operator can lead to loss of information. You can disable this operator by defining <tt>QT_NO_CAST_TO_ASCII</tt> when you compile your applications. You then need to call [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]]() (or [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]]() or [[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]]() or [[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]]()) explicitly if you want to convert the data to <tt>const char *</tt> and pass the return value on to the std::string constructor.

This operator is only available if Qt is configured with STL compatibility enabled.

See also [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]](), [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]](), [[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]](), and [[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]]().

===<div id="toStdWString"></div>std::wstring QString::toStdWString () const===

Returns a std::wstring object with the data contained in this [[Qt:Документация 4.3.2/qstring | QString]]. The std::wstring is encoded in utf16 on platforms where wchar_t is 2 bytes wide (e.g&#x2e; windows) and in ucs4 on platforms where wchar_t is 4 bytes wide (most Unix systems).

This operator is mostly useful to pass a [[Qt:Документация 4.3.2/qstring | QString]] to a function that accepts a std::wstring object.

This operator is only available if Qt is configured with STL compatibility enabled.

See also [[Qt:Документация 4.3.2/qstring#utf16 | utf16]](), [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]](), [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]](), [[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]](), and [[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]]().

===<div id="toUInt"></div>[[Qt:Документация 4.3.2/qtglobal#uint-typedef | uint]] QString::toUInt ( bool * ''ok'' = 0, int ''base'' = 10 ) const===

Returns the string converted to an <tt>unsigned int</tt> using base ''base'', which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If a conversion error occurs, *''ok'' is set to false; otherwise *''ok'' is set to true.

If ''base'' is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

Example:
<source lang="cpp-qt">     QString str = "FF";
     bool ok;

     uint hex = str.toUInt(&amp;ok, 16);     // hex == 255, ok == true
     uint dec = str.toUInt(&amp;ok, 10);     // dec == 0, ok == false</source> 
See also [[Qt:Документация 4.3.2/qstring#number | number]]() and [[Qt:Документация 4.3.2/qstring#toInt | toInt]]().

===<div id="toULong"></div>[[Qt:Документация 4.3.2/qtglobal#ulong-typedef | ulong]] QString::toULong ( bool * ''ok'' = 0, int ''base'' = 10 ) const===

Returns the string converted to an <tt>unsigned long</tt> using base ''base'', which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If a conversion error occurs, *''ok'' is set to false; otherwise *''ok'' is set to true.

If ''base'' is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

Example:
<source lang="cpp-qt">     QString str = "FF";
     bool ok;

     ulong hex = str.toULong(&amp;ok, 16);   // hex == 255, ok == true
     ulong dec = str.toULong(&amp;ok, 10);   // dec == 0, ok == false</source> 
See also [[Qt:Документация 4.3.2/qstring#number | number]]().

===<div id="toULongLong"></div>[[Qt:Документация 4.3.2/qtglobal#qulonglong-typedef | qulonglong]] QString::toULongLong ( bool * ''ok'' = 0, int ''base'' = 10 ) const===

Returns the string converted to an <tt>unsigned long long</tt> using base ''base'', which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If a conversion error occurs, *''ok'' is set to false; otherwise *''ok'' is set to true.

If ''base'' is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

Example:
<source lang="cpp-qt">     QString str = "FF";
     bool ok;

     quint64 hex = str.toULongLong(&amp;ok, 16);    // hex == 255, ok == true
     quint64 dec = str.toULongLong(&amp;ok, 10);    // dec == 0, ok == false</source> 
See also [[Qt:Документация 4.3.2/qstring#number | number]]() and [[Qt:Документация 4.3.2/qstring#toLongLong | toLongLong]]().

===<div id="toUShort"></div>[[Qt:Документация 4.3.2/qtglobal#ushort-typedef | ushort]] QString::toUShort ( bool * ''ok'' = 0, int ''base'' = 10 ) const===

Returns the string converted to an <tt>unsigned short</tt> using base ''base'', which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If a conversion error occurs, *''ok'' is set to false; otherwise *''ok'' is set to true.

If ''base'' is 0, the C language convention is used: If the string begins with "0x", base 16 is used; if the string begins with "0", base 8 is used; otherwise, base 10 is used.

Example:
<source lang="cpp-qt">     QString str = "FF";
     bool ok;

     ushort hex = str.toUShort(&amp;ok, 16);     // hex == 255, ok == true
     ushort dec = str.toUShort(&amp;ok, 10);     // dec == 0, ok == false</source> 
See also [[Qt:Документация 4.3.2/qstring#number | number]]() and [[Qt:Документация 4.3.2/qstring#toShort | toShort]]().

===<div id="toUcs4"></div>[[Qt:Документация 4.3.2/qvector | QVector]]<[[Qt:Документация 4.3.2/qtglobal#uint-typedef | uint]]> QString::toUcs4 () const===

Returns a UCS-4 representation of the string as a [[Qt:Документация 4.3.2/qvector | QVector]]<uint>.

This function was introduced in Qt 4.2.

See also [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]](), [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]](), [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]](), [[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]](), [[Qt:Документация 4.3.2/qtextcodec | QTextCodec]], [[Qt:Документация 4.3.2/qstring#fromUcs4 | fromUcs4]](), and [[Qt:Документация 4.3.2/qstring#toWCharArray | toWCharArray]]().

===<div id="toUpper"></div>QString QString::toUpper () const===

Returns an uppercase copy of the string.
<source lang="cpp-qt">     QString str = "TeXt";
     str = str.toUpper();        // str == "TEXT"</source> 
See also [[Qt:Документация 4.3.2/qstring#toLower | toLower]]().

===<div id="toUtf8"></div>[[Qt:Документация 4.3.2/qbytearray | QByteArray]] QString::toUtf8 () const===

Returns a UTF-8 representation of the string as a [[Qt:Документация 4.3.2/qbytearray | QByteArray]].

See also [[Qt:Документация 4.3.2/qstring#fromUtf8 | fromUtf8]](), [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]](), [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]](), [[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]](), and [[Qt:Документация 4.3.2/qtextcodec | QTextCodec]].

===<div id="toWCharArray"></div>int QString::toWCharArray ( wchar_t * ''array'' ) const===

Fills the ''array'' with the data contained in this [[Qt:Документация 4.3.2/qstring | QString]] object. The array is encoded in utf16 on platforms where wchar_t is 2 bytes wide (e.g&#x2e; windows) and in ucs4 on platforms where wchar_t is 4 bytes wide (most Unix systems).

''array'' has to be allocated by the caller and contain enough space to hold the complete string (allocating the array with the same length as the string is always sufficient).

returns the actual length of the string in ''array''.

This function was introduced in Qt 4.2.

See also [[Qt:Документация 4.3.2/qstring#utf16 | utf16]](), [[Qt:Документация 4.3.2/qstring#toUcs4 | toUcs4]](), [[Qt:Документация 4.3.2/qstring#toAscii | toAscii]](), [[Qt:Документация 4.3.2/qstring#toLatin1 | toLatin1]](), [[Qt:Документация 4.3.2/qstring#toUtf8 | toUtf8]](), [[Qt:Документация 4.3.2/qstring#toLocal8Bit | toLocal8Bit]](), and [[Qt:Документация 4.3.2/qstring#toStdWString | toStdWString]]().

===<div id="trimmed"></div>QString QString::trimmed () const===

Returns a string that has whitespace removed from the start and the end.

Whitespace means any character for which [[Qt:Документация 4.3.2/qchar#isSpace | QChar::isSpace]]() returns true. This includes the ASCII characters '\t', '\n', '\v', '\f', '\r', and ' '.

Example:
<source lang="cpp-qt">     QString str = "  lots\t of\nwhitespace\r\n ";
     str = str.trimmed();
     // str == "lots\t of\nwhitespace"</source> 
Unlike [[Qt:Документация 4.3.2/qstring#simplified | simplified]](), trimmed() leaves internal whitespace alone.

See also [[Qt:Документация 4.3.2/qstring#simplified | simplified]]().

===<div id="truncate"></div>void QString::truncate ( int ''position'' )===

Truncates the string at the given ''position'' index.

If the specified ''position'' index is beyond the end of the string, nothing happens.

Example:
<source lang="cpp-qt">     QString str = "Vladivostok";
     str.truncate(4);
     // str == "Vlad"</source> 
See also [[Qt:Документация 4.3.2/qstring#chop | chop]](), [[Qt:Документация 4.3.2/qstring#resize | resize]](), and [[Qt:Документация 4.3.2/qstring#left | left]]().

===<div id="unicode"></div>const [[Qt:Документация 4.3.2/qchar | QChar]] * QString::unicode () const===

Returns a '\0'-terminated Unicode representation of the string. The result remains valid until the string is modified.

See also [[Qt:Документация 4.3.2/qstring#setUnicode | setUnicode]]() and [[Qt:Документация 4.3.2/qstring#utf16 | utf16]]().

===<div id="utf16"></div>const [[Qt:Документация 4.3.2/qtglobal#ushort-typedef | ushort]] * QString::utf16 () const===

Returns the [[Qt:Документация 4.3.2/qstring | QString]] as a '\0'-terminated array of unsigned shorts. The result remains valid until the string is modified.

See also [[Qt:Документация 4.3.2/qstring#setUtf16 | setUtf16]]() and [[Qt:Документация 4.3.2/qstring#unicode | unicode]]().

===<div id="vsprintf"></div>QString &amp; QString::vsprintf ( const char * ''cformat'', va_list ''ap'' )===

Equivalent method to [[Qt:Документация 4.3.2/qstring#sprintf | sprintf]](), but takes a va_list ''ap'' instead a list of variable arguments. See the [[Qt:Документация 4.3.2/qstring#sprintf | sprintf]]() documentation for an explanation of ''cformat''.

This method does not call the va_end macro, the caller is responsible to call va_end on ''ap''.

See also [[Qt:Документация 4.3.2/qstring#sprintf | sprintf]]().

===<div id="operator-not-eq"></div>bool QString::operator!= ( const QString &amp; ''other'' ) const===

Returns true if this string is not equal to string ''other''; otherwise returns false.

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-interface strings with [[Qt:Документация 4.3.2/qstring#localeAwareCompare | localeAwareCompare]]().

===<div id="operator-not-eq-2"></div>bool QString::operator!= ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

===<div id="operator-not-eq-3"></div>bool QString::operator!= ( const [[Qt:Документация 4.3.2/qbytearray | QByteArray]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' byte array is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-not-eq-4"></div>bool QString::operator!= ( const char * ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' const char pointer is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-2b-eq"></div>QString &amp; QString::operator+= ( const QString &amp; ''other'' )===

Appends the string ''other'' onto the end of this string and returns a reference to this string.

Example:
<source lang="cpp-qt">     QString x = "free";
     QString y = "dom";
     x += y;
     // x == "freedom"</source> 
This operation is typically very fast ([[Qt:Документация 4.3.2/containers#constant-time | constant time]]), because [[Qt:Документация 4.3.2/qstring | QString]] preallocates extra space at the end of the string data so it can grow without reallocating the entire string each time.

See also [[Qt:Документация 4.3.2/qstring#append | append]]() and [[Qt:Документация 4.3.2/qstring#prepend | prepend]]().

===<div id="operator-2b-eq-2"></div>QString &amp; QString::operator+= ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''str'' )===

This is an overloaded member function, provided for convenience.

Appends the Latin-1 string ''str'' to this string.

===<div id="operator-2b-eq-3"></div>QString &amp; QString::operator+= ( const [[Qt:Документация 4.3.2/qbytearray | QByteArray]] &amp; ''ba'' )===

This is an overloaded member function, provided for convenience.

Appends the byte array ''ba'' to this string. The byte array is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this function by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-2b-eq-4"></div>QString &amp; QString::operator+= ( const char * ''str'' )===

This is an overloaded member function, provided for convenience.

Appends the string ''str'' to this string. The const char pointer is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this function by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-2b-eq-5"></div>QString &amp; QString::operator+= ( char ''ch'' )===

This is an overloaded member function, provided for convenience.

Appends the character ''ch'' to this string. The character is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this function by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-2b-eq-6"></div>QString &amp; QString::operator+= ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'' )===

This is an overloaded member function, provided for convenience.

Appends the character ''ch'' to the string.

===<div id="operator-lt"></div>bool QString::operator< ( const QString &amp; ''other'' ) const===

Returns true if this string is lexically less than string ''other''; otherwise returns false.

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-interface strings using the [[Qt:Документация 4.3.2/qstring#localeAwareCompare | QString::localeAwareCompare]]() function.

===<div id="operator-lt-2"></div>bool QString::operator< ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

===<div id="operator-lt-3"></div>bool QString::operator< ( const [[Qt:Документация 4.3.2/qbytearray | QByteArray]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' byte array is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-lt-4"></div>bool QString::operator< ( const char * ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' const char pointer is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-lt-eq"></div>bool QString::operator<= ( const QString &amp; ''other'' ) const===

Returns true if this string is lexically less than or equal to string ''other''; otherwise returns false.

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-interface strings with [[Qt:Документация 4.3.2/qstring#localeAwareCompare | localeAwareCompare]]().

===<div id="operator-lt-eq-2"></div>bool QString::operator<= ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

===<div id="operator-lt-eq-3"></div>bool QString::operator<= ( const [[Qt:Документация 4.3.2/qbytearray | QByteArray]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' byte array is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-lt-eq-4"></div>bool QString::operator<= ( const char * ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' const char pointer is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-eq"></div>QString &amp; QString::operator= ( const QString &amp; ''other'' )===

Assigns ''other'' to this string and returns a reference to this string.

===<div id="operator-eq-3"></div>QString &amp; QString::operator= ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''str'' )===

This is an overloaded member function, provided for convenience.

Assigns the Latin-1 string ''str'' to this string.

===<div id="operator-eq-4"></div>QString &amp; QString::operator= ( const [[Qt:Документация 4.3.2/qbytearray | QByteArray]] &amp; ''ba'' )===

This is an overloaded member function, provided for convenience.

Assigns ''ba'' to this string. The byte array is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-eq-5"></div>QString &amp; QString::operator= ( const char * ''str'' )===

This is an overloaded member function, provided for convenience.

Assigns ''str'' to this string. The const char pointer is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-eq-6"></div>QString &amp; QString::operator= ( char ''ch'' )===

This is an overloaded member function, provided for convenience.

Assigns character ''ch'' to this string. The character is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-eq-7"></div>QString &amp; QString::operator= ( [[Qt:Документация 4.3.2/qchar | QChar]] ''ch'' )===

This is an overloaded member function, provided for convenience.

Sets the string to contain the single character ''ch''.

===<div id="operator-eq-eq"></div>bool QString::operator== ( const QString &amp; ''other'' ) const===

Returns true if string ''other'' is equal to this string; otherwise returns false.

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-interface strings with [[Qt:Документация 4.3.2/qstring#localeAwareCompare | localeAwareCompare]]().

===<div id="operator-eq-eq-2"></div>bool QString::operator== ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

===<div id="operator-eq-eq-3"></div>bool QString::operator== ( const [[Qt:Документация 4.3.2/qbytearray | QByteArray]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' byte array is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-eq-eq-4"></div>bool QString::operator== ( const char * ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' const char pointer is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-gt"></div>bool QString::operator> ( const QString &amp; ''other'' ) const===

Returns true if this string is lexically greater than string ''other''; otherwise returns false.

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-interface strings with [[Qt:Документация 4.3.2/qstring#localeAwareCompare | localeAwareCompare]]().

===<div id="operator-gt-2"></div>bool QString::operator> ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

===<div id="operator-gt-3"></div>bool QString::operator> ( const [[Qt:Документация 4.3.2/qbytearray | QByteArray]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' byte array is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-gt-4"></div>bool QString::operator> ( const char * ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' const char pointer is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-gt-eq"></div>bool QString::operator>= ( const QString &amp; ''other'' ) const===

Returns true if this string is lexically greater than or equal to string ''other''; otherwise returns false.

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-interface strings with [[Qt:Документация 4.3.2/qstring#localeAwareCompare | localeAwareCompare]]().

===<div id="operator-gt-eq-2"></div>bool QString::operator>= ( const [[Qt:Документация 4.3.2/qlatin1string | QLatin1String]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

===<div id="operator-gt-eq-3"></div>bool QString::operator>= ( const [[Qt:Документация 4.3.2/qbytearray | QByteArray]] &amp; ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' byte array is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-gt-eq-4"></div>bool QString::operator>= ( const char * ''other'' ) const===

This is an overloaded member function, provided for convenience.

The ''other'' const char pointer is converted to a [[Qt:Документация 4.3.2/qstring | QString]] using the [[Qt:Документация 4.3.2/qstring#fromAscii | fromAscii]]() function.

You can disable this operator by defining <tt>QT_NO_CAST_FROM_ASCII</tt> when you compile your applications. This can be useful if you want to ensure that all user-visible strings go through [[Qt:Документация 4.3.2/qobject#tr | QObject::tr]](), for example.

===<div id="operator-5b-5d"></div>QCharRef QString::operator[] ( int ''position'' )===

Returns the character at the specified ''position'' in the string as a modifiable reference.

Example:
<source lang="cpp-qt">     QString str;

     if (str[0] == QChar('?'))
         str[0] = QChar('_');</source> 
The return value is of type QCharRef, a helper class for [[Qt:Документация 4.3.2/qstring | QString]]. When you get an object of type QCharRef, you can use it as if it were a [[Qt:Документация 4.3.2/qchar | QChar]] &amp;. If you assign to it, the assignment will apply to the character in the [[Qt:Документация 4.3.2/qstring | QString]] from which you got the reference.

See also [[Qt:Документация 4.3.2/qstring#at | at]]().

===<div id="operator-5b-5d-2"></div>const [[Qt:Документация 4.3.2/qchar | QChar]] QString::operator[] ( int ''position'' ) const===

This is an overloaded member function, provided for convenience.

===<div id="operator-5b-5d-3"></div>QCharRef QString::operator[] ( [[Qt:Документация 4.3.2/qtglobal#uint-typedef | uint]] ''position'' )===

This is an overloaded member function, provided for convenience.

Returns the character at the specified ''position'' in the string as a modifiable reference. Equivalent to <tt>at(position)</tt>.

===<div id="operator-5b-5d-4"></div>const [[Qt:Документация 4.3.2/qchar | QChar]] QString::operator[] ( [[Qt:Документация 4.3.2/qtglobal#uint-typedef | uint]] ''position'' ) const===

This is an overloaded member function, provided for convenience.
<hr />
==Связанные не-члены==

===<div id="operator-not-eq-44"></div>bool operator!= ( const char * ''s1'', const QString &amp; ''s2'' )===

This is an overloaded member function, provided for convenience.

Returns true if ''s1'' is not equal to ''s2''; otherwise returns false.

For ''s1'' != 0, this is equivalent to <tt>compare(</tt> ''s1'', ''s2'' <tt>) != 0</tt>. Note that no string is equal to ''s1'' being 0.

See also [[Qt:Документация 4.3.2/qstring#compare | QString::compare]]().

===<div id="operator-2b-8"></div>const QString operator+ ( const QString &amp; ''s1'', const QString &amp; ''s2'' )===

This is an overloaded member function, provided for convenience.

Returns a string which is the result of concatenating ''s1'' and ''s2''.

===<div id="operator-2b-25"></div>const QString operator+ ( const QString &amp; ''s1'', const char * ''s2'' )===

This is an overloaded member function, provided for convenience.

Returns a string which is the result of concatenating ''s1'' and ''s2'' (''s2'' is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | QString::fromAscii]]() function).

See also [[Qt:Документация 4.3.2/qstring#fromAscii | QString::fromAscii]]().

===<div id="operator-2b-26"></div>const QString operator+ ( const char * ''s1'', const QString &amp; ''s2'' )===

This is an overloaded member function, provided for convenience.

Returns a string which is the result of concatenating ''s1'' and ''s2'' (''s1'' is converted to Unicode using the [[Qt:Документация 4.3.2/qstring#fromAscii | QString::fromAscii]]() function).

See also [[Qt:Документация 4.3.2/qstring#fromAscii | QString::fromAscii]]().

===<div id="operator-2b-27"></div>const QString operator+ ( const QString &amp; ''s'', char ''ch'' )===

This is an overloaded member function, provided for convenience.

Returns a string which is the result of concatenating the string ''s'' and the character ''ch''.

===<div id="operator-2b-28"></div>const QString operator+ ( char ''ch'', const QString &amp; ''s'' )===

This is an overloaded member function, provided for convenience.

Returns a string which is the result of concatenating the character ''ch'' and the string ''s''.

===<div id="operator-lt-18"></div>bool operator< ( const char * ''s1'', const QString &amp; ''s2'' )===

This is an overloaded member function, provided for convenience.

Returns true if ''s1'' is lexically less than ''s2''; otherwise returns false. For ''s1'' != 0, this is equivalent to <tt>compare(s1, s2) < 0</tt>.

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-interface strings using the [[Qt:Документация 4.3.2/qstring#localeAwareCompare | QString::localeAwareCompare]]() function.

See also [[Qt:Документация 4.3.2/qstring#compare | QString::compare]]().

===<div id="operator-lt-lt-56"></div>[[Qt:Документация 4.3.2/qdatastream | QDataStream]] &amp; operator<< ( [[Qt:Документация 4.3.2/qdatastream | QDataStream]] &amp; ''stream'', const QString &amp; ''string'' )===

This is an overloaded member function, provided for convenience.

Writes the given ''string'' to the specified ''stream''.

See also [[Qt:Документация 4.3.2/datastreamformat | Format of the QDataStream Operators]].

===<div id="operator-lt-eq-15"></div>bool operator<= ( const char * ''s1'', const QString &amp; ''s2'' )===

This is an overloaded member function, provided for convenience.

Returns true if ''s1'' is lexically less than or equal to ''s2''; otherwise returns false. For ''s1'' != 0, this is equivalent to <tt>compare(s1, s2) <= 0</tt>.

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-interface strings with [[Qt:Документация 4.3.2/qstring#localeAwareCompare | QString::localeAwareCompare]]().

See also [[Qt:Документация 4.3.2/qstring#compare | QString::compare]]().

===<div id="operator-eq-eq-60"></div>bool operator== ( const char * ''s1'', const QString &amp; ''s2'' )===

This is an overloaded member function, provided for convenience.

Returns true if ''s1'' is equal to ''s2''; otherwise returns false. Note that no string is equal to ''s1'' being 0.

Equivalent to <tt>s1 != 0 &amp;&amp; compare(s1, s2) == 0</tt>.

See also [[Qt:Документация 4.3.2/qstring#compare | QString::compare]]().

===<div id="operator-gt-15"></div>bool operator> ( const char * ''s1'', const QString &amp; ''s2'' )===

This is an overloaded member function, provided for convenience.

Returns true if ''s1'' is lexically greater than ''s2''; otherwise returns false. Equivalent to <tt>compare(s1, s2) > 0</tt>.

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-interface strings using the [[Qt:Документация 4.3.2/qstring#localeAwareCompare | QString::localeAwareCompare]]() function.

See also [[Qt:Документация 4.3.2/qstring#compare | QString::compare]]().

===<div id="operator-gt-eq-15"></div>bool operator>= ( const char * ''s1'', const QString &amp; ''s2'' )===

This is an overloaded member function, provided for convenience.

Returns true if ''s1'' is lexically greater than or equal to ''s2''; otherwise returns false. For ''s1'' != 0, this is equivalent to <tt>compare(s1, s2) >= 0</tt>.

The comparison is based exclusively on the numeric Unicode values of the characters and is very fast, but is not what a human would expect. Consider sorting user-interface strings using the [[Qt:Документация 4.3.2/qstring#localeAwareCompare | QString::localeAwareCompare]]() function.

===<div id="operator-gt-gt-33"></div>[[Qt:Документация 4.3.2/qdatastream | QDataStream]] &amp; operator>> ( [[Qt:Документация 4.3.2/qdatastream | QDataStream]] &amp; ''stream'', QString &amp; ''string'' )===

This is an overloaded member function, provided for convenience.

Reads a string from the specified ''stream'' into the given ''string''.

See also [[Qt:Документация 4.3.2/datastreamformat | Format of the QDataStream Operators]].
<hr />
==Macro Documentation==

===<div id="QT_NO_CAST_FROM_ASCII"></div>QT_NO_CAST_FROM_ASCII===

Disables automatic conversions from 8-bit strings (char *) to unicode QStrings

See also [[Qt:Документация 4.3.2/qstring#QT_NO_CAST_TO_ASCII | QT_NO_CAST_TO_ASCII]].

===<div id="QT_NO_CAST_TO_ASCII"></div>QT_NO_CAST_TO_ASCII===

disables automatic conversion from [[Qt:Документация 4.3.2/qstring | QString]] to ASCII 8-bit strings (char *)

See also [[Qt:Документация 4.3.2/qstring#QT_NO_CAST_FROM_ASCII | QT_NO_CAST_FROM_ASCII]].

{{Qt4.3.2_footer}}