super.md

Super

If you define a method of the same name as a parent's method, the child method takes priority.

bikecontainer.rb :

module BikeContainer
	
	def dock(bike)
	@bikes << bike

end

garage.rb :

class Garage

	include BikeContainer

	def dock(bike)
		bike.fix!
		@bikes << bike
	end

end

But there's a better way. Use super to call the parent's method. By doing this, you can define a custom child method (here, we want each Garage to fix the bike as well as docking it) without repeating yourself from the original method.

class Garage

	include BikeContainer

	def dock(bike)
		bike.fix!
		super  # Runs the original dock method from BikeContainer
	end

end

You can also call arguments on super. Say you have a Ship class which takes an argument of the ship size:

class Ship
  attr_reader: size

  def initialize(size)
    @size = size
  end
end

Now you can define the subclass, using super to call the parent method with a given argument.

class Submarine < Ship
  def initialize
    super(2) # calls Ship's initialize method with arg of 2
  end
end

You could make this clearer by using a constant in the subclass:

class Submarine < Ship
  SIZE = 3
  def initialize
    super SIZE
  end
end

You can also use super in string interpolation, like this:

puts "#{super}"