How to Check if an Object Is "nil" in Ruby?

In Ruby, you can check if an object is nil by using the NilClass#nil? method, which returns a boolean true only if the object is nil, and false otherwise:

puts nil.nil? #=> true

puts "foo".nil? #=> false
puts false.nil? #=> false
puts 0.nil? #=> false
# ...

For example:

my_obj = nil

if my_obj.nil?
  puts "object is nil"
else
  puts "object is not nil"
end

#=> "object is nil"

This will output "object is nil" because my_obj is nil.

As an alternative, you can also use the == operator to check if an object is equal to nil:

my_obj = nil

if my_obj == nil
  puts "object is nil"
else
  puts "object is not nil"
end

#=> "object is nil"

This will also output "object is nil". However, it's more idiomatic to use the NilClass#nil? method when checking for nil in Ruby.