What is ruby nil?

Posted in Tutorials

nil is ruby’s singleton object.  It is an instance of the NilClass which you can see when you do …

nil.class

and it returns NilClass

Because nil is an singleton, there is always exactly one instance of the NilClass and that is nil.

So

nil == nil

is always true.

How to determine if an object is does not exist?

if foobar.nil?
puts “No foobar”
else
puts “Has foobar”
end

---