Ruby/Language Basics/Boolean Operators

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And, or and Not

iAmChris  = true
iAmPurple = false
iLikeFood = true
iEatRocks = false
puts (iAmChris  and iLikeFood)
puts (iLikeFood and iEatRocks)
puts (iAmPurple and iLikeFood)
puts (iAmPurple and iEatRocks)
puts
puts (iAmChris  or iLikeFood)
puts (iLikeFood or iEatRocks)
puts (iAmPurple or iLikeFood)
puts (iAmPurple or iEatRocks)
puts
puts (not iAmPurple)
puts (not iAmChris )
# true
# false
# false
# false
# true
# true
# true
# false
# true
# false



Are more than two statements OK?

a = b = c = d = 2
if a == 10 || b == 27 || c = 43 || d = -14
  print sum = a + b + c + d
end



Chaining together multiple comparisons is also possible with a clever use of parentheses:

age = 24
gender = "male"
puts "You"re a working age man" if gender == "male" && (age >= 18 && age <= 65)



check whether one or the other is true by using ||

age = 24
puts "You"re either very young or very old" if age > 80 || age < 10



have more than two statements separated by &&

a = 1
b = 2
c = 3
d = 4
if a == 10 && b == 27 && c == 43 && d == -14
  print sum = a + b + c + d
end



|| operator is or.

# When you use || or or, if any of the statements are true, the code executes:
ruby = "nifty"
programming = "fun"
if ruby == "nifty" or programming == "fun"
  puts "or!"
end



the && operator means "and."

ruby = "nifty"
programming = "fun"
if ruby == "nifty" && programming == "fun"
  puts "and"
end



Use or in if statement

puts "Hello, what\"s your name?"
name = gets.chomp
puts "Hello, " + name + "."
if (name == "Chris" or name == "Katy")
  puts "What a lovely name!"
end



use the keyword and instead of &&.

ruby = "nifty"
programming = "fun"
if ruby == "nifty" and programming == "fun"
  puts " and and"
end