True, False, and Nil In Ruby
Ruby is an open-sourced object-oriented programming language developed by Yukihiro Matsumoto. In Ruby, everything is treated as an object. true, false and nil are built-in data types of Ruby.
Note: Always remember in Ruby true, false, and nil are objects, not numbers. Whenever Ruby requires a Boolean value, then nil behaves like false and values other than nil or false behave like true.
True and False
In Ruby, true and false are boolean values that represent yes and no. true is an object of TrueClass and false is an object of FalseClass.
Note: Ruby does not contain Boolean class.
Let’s see a few examples of true and false in Ruby.
Example 1:
Ruby
# Ruby program to illustrate the use # of true and false a = 4 b = 4 if a == b # If Condition is true puts "True! a and b are equal" else # If Condition is false puts "False! a and b are not equal" end |
Output:
True! a and b are equal
Example 2:
Ruby
# Ruby program to illustrate the use # of true and false a1 = "w3wiki" b1 = "w3wiki" result1 = a1 == b1 puts result1 a2 = "w3wiki" b2 = "Beginner" result2 = a2 == b2 puts result2 |
Output:
true false
Example 3:
Ruby
# Ruby program to illustrate the use # of true and false # If condition is true if 55 == 55 puts "w3wiki !" # If Condition is false else puts " A Computer Science Portal for Beginner!" end |
Output:
w3wiki !
Nil
In Ruby, nil is a special value that denotes the absence of any value. Nil is an object of NilClass. nil is Ruby’s way of referring to nothing or void. Ruby also provide a nil? method to detect if any object is nil or not.
Example 1:
Ruby
# Checking for nil's class a = nil . class puts a |
Output:
NilClass
Example 2:
Ruby
# Ruby program to illustrate nil? method # Checking for Nil array = [ 1 , 2 , 3 , 4 , 5 ] # Since array[5] does not exist so, it is nil. result1 = array[ 5 ]. nil ? puts result1 # Since array[2] exists so, it is not nil. result2 = array[ 2 ]. nil ? puts result2 |
Output:
true false
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