Inheritance

Inheritance

A class inherits from another with class Dog < Animal, gaining all of the parent's public and protected methods. This models an "is-a" relationship, like a Dog being a kind of Animal. Ruby only supports single inheritance for classes -- a class can have just one direct superclass, though modules (covered later) offer another way to share behavior.

Note: Ruby supports single inheritance only for classes -- use modules (Mixins) to share behavior across unrelated class hierarchies.

Example: Inheritance

class Animal
  def initialize(name)
    @name = name
  end

  def eat
    puts "#{@name} is eating"
  end
end

class Dog < Animal
  def bark
    puts "#{@name} says Woof!"
  end
end

rex = Dog.new("Rex")
rex.eat
rex.bark