Ruby/Number/Numeric class
Материал из Wiki.crossplatform.ru
Версия от 17:10, 26 мая 2010; (Обсуждение)
Find out the modules Numeric class resides
p Numeric.included_modules # => [Comparable, Kernel]
Get the ceiling or floor of a number (from Float, Integer, or Numeric):
4.65.ceil # => 5 4.65.floor # => 4
Get the next integer with next (or its alias succ):
-24.next # => -23 1.next # => 2 999.next # => 1000
Is a number integer
num = 4 if num.integer? puts "Invited guests: " + num.to_s else puts "Only whole persons can come to this party." end
More Math Methods
# Get the absolute value of a number (Bignum, Complex, Fixnum, Float, Numeric, Rational) -40.abs # => 40 40.abs # => 40
Or round a number up or down (Float, Integer, or Numeric):
100.45.round # => 100 100.49.round # => 100 100.5.round # => 101 100.6.round # => 101
The integer? method comes from the Numeric class
12.integer? # => true 12.0.integer? # => false -1.integer? # => true -12.integer? # => true
