Polymorphic sample

polymorphic_sample.rb

class Animal
  def name
    'animal'
  end
end

class Cow < Animal
  def name
    'cow'
  end
end

class Chicken < Animal
  def name
    'chicken'
  end
end

class Farm
  attr_accessor :animals
  
  def initalize(animals)
    @animals = animals
  end
  
  def animal_names
    animals.map(&:name)
  end
  
  def self.animal_names
    animals = [Cow, Chicken].map(&:new)
    new(animals).animal_names
  end
end