Ruby/Class/child class

#!/usr/bin/env ruby
class Hello
  def howdy
    greeting = "Hello, myValue!"
    puts greeting
  end
end
class Goodbye < Hello
  def solong
    farewell = "Goodbye, myValue."
    puts farewell
  end
end
friendly = Goodbye.new
friendly.howdy
friendly.solong

class Pet
  attr_accessor :name, :age, :gender, :color
end
class Cat < Pet
end
class Dog < Pet
  def bark
    puts "Woof!"
  end
end

class Pet
  attr_accessor :name, :age, :gender, :color
end
class Cat < Pet
end
class Dog < Pet
end
class Snake < Pet
  attr_accessor :length
end

class Pet
  attr_accessor :name, :age, :gender, :color
end
class Cat < Pet
end
class Dog < Pet
  def bark
    puts "Woof!"
  end
end
 
a_dog = Dog.new
puts a_dog.class