Booleans and nil in Ruby on Rails
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Today, we will learn about boolean and nil values in Ruby on Rails. Lets start with what these are.
What is a boolean?
A boolean value is used to represent whether the condition or the logic is true or false. In Ruby, we have boolean objects as "true" and "false".
str1 = "Hello"
str2 = "Hello"
result1 = str1 ==str2
puts result1
int1 = 5
int2 = 3
result2 = int1 == int2
puts result2
Output:
true
false
What is nil?
A "nil" is used to indicate "no value" or "unknown." In Ruby, nil is an object of Nilclass.
# Checking for Nil
array = [ 1, 2, 3]
# Here, array[4] does not exist so, it is nil.
result1 = array[4].nil?
puts result1
# here, array[2] exists so, it is not nil.
result2 = array[2].nil?
puts result2
Output:
true
false
In Ruby, only nil
and false
are false and everything
else is true. Lets take an example:
if subscription
puts "We have subscribed"
end
Here, Ruby checks if the subscription is true or false/nil before printing the string.
In some cases, if we have to call the method on an object like this:
if subscription.date
puts "Subscribed date"
end
This may lead us to error it the paid is nil, to avoid error we can use the safe navigator like this.
if subscription&.date
puts "Subscribed date"
end
Booleans Methods
Any methods ending with question marks are the boolean methods. They return either true or false. Some examples of Boolean methods are:
def empty?
............
end
def paid?
....................
end
Hope have learned something about boolean in Ruby today. Thank you for reading. Happy Reading !! Keep Learning. :)