How does Inheritance work in Ruby?

Inheritance is a key aspect of any OOP language. With the help of inheritance, we can reuse the methods that are defined on the parent class (also known as superclass) in the child class (also known as subclass).

In Ruby, single class inheritance is supported, which means that one class can inherit from the other class, but it can't inherit from two super classes. In order to achieve multiple inheritance, Ruby provides something called mixins that one can make use of.

Inheritance helps in improving the code reusability, as the developer won't have to create the same method again that has already been defined for the parent class. The developer can inherit the parent class and then call the method.

There are two important terms in inheritance and these are mentioned below −

• Super class − A class whose characteristics are inherited by the subclass.

• Subclass − A class that is inheriting the characteristics of the superclass.

Now that we know a little bit about the inheritance in Ruby, let's take a couple of examples to understand how it works in a better way.

Example 1

# Inheritance in Ruby #!/usr/bin/ruby # Super class or parent class class TutorialsPoint    # constructor of super class    def initialize       puts "Superclass"    end    # method of the superclass    def super_method       puts "Method of superclass"    end end # subclass or derived class class Learn_Ruby < TutorialsPoint    # constructor of derived class    def initialize    puts "Subclass"    end end # creating object of superclass TutorialsPoint.new # creating object of subclass sub_obj = Learn_Ruby.new # calling superclass method sub_obj.super_method

Output

Superclass Subclass Method of superclass

Example 2

Now let's consider one more example where we will override the parent class method in the subclass with a little bit of change.

# Inheritance in Ruby #!/usr/bin/ruby # Super class or parent class class TutorialsPoint    # constructor of super class    def initialize       puts "Superclass"    end    # method of the superclass    def super_method       puts "superclass method"    end end # subclass or derived class class Learn_Ruby < TutorialsPoint    # constructor of derived class    def super_method    puts "subclass method"    end end # creating object of superclass TutorialsPoint.new # creating object of subclass sub_obj = Learn_Ruby.new # calling superclass method sub_obj.super_method

Output

Superclass Superclass subclass method