Overriding the == operator in Ruby

Question

According to the docs, Array.include? uses the == comparison on objects. I come from Java where such things are (usually) done with .equals() which is easy to override for a particular object.

How can I override == in Ruby to allow me to specify the behaviour of Array.include? for my particular object?

Answer 1

In Ruby == is just a method (with some syntax sugar on top allowing you to write foo == bar instead of foo.==(bar)) and you override == just like you would any other method:

class MyClass   def ==(other_object)     # return true if self is equal to other_object, false otherwise   end end 

Answer 2

As described above, == is a method in Ruby and can be overridden. You code a custom equality condition in the method. For example:

class Person   attr_reader :name, :gender, :social_id   attr_accessor :age    def initialize(name, age, gender, social_id)     self.name = name     self.age = age.to_i     self.gender = gender     self.social_id = social_id   end    def ==(other)     social_id == other.social_id   end end 

You don't need to override other methods any more.