James Ladd OO discussion

001_conditional.rb

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

  def speak
    if @type == :cow
      "moo"
    elsif @type == :dog
      "woof"
    elsif @type == :sparrow
      "african or european?"
    end
  end
end

002_hashed.rb

class Animal
  SPEECH_TYPES = {:cow => "moo", :dog => "woof", :sparrow => "african or european?"}

  def initialize(type)
    @type = type
  end

  def speak
    SPEECH_TYPES[@type]
  end
end

003_duplication.rb

class Animal
  SPEECH_TYPES = {:cow => "moo", :dog => "woof", :sparrow => "african or european?"}
  MOVEMENT_TYPES = {:cow => "walk", :dog => "run", :sparrow => "fly"}

  def initialize(type)
    @type = type
  end

  def speak
    SPEECH_TYPES[@type]
  end

  def move
    MOVEMENT_TYPES[@type]
  end
end

004_oo.rb

class Animal
  def self.new_cow
    new "moo", "walk"
  end

  def self.new_dog
    new "woof", "run"
  end

  def self.new_sparrow
    new "african or european?", "fly"
  end

  def initialize(speech, movement)
    @speach = speech
    @movement = movement
  end

  def speak
    @speach
  end

  def move
    @movement
  end
end