oop.rb

class Dog # class name is a "constant"
  # Objects combine:
  # -- state (instance variables)
  # -- behavior (methods)

  def initialize
    # first step in the object's lifecycle
    # do i have any setup i actually need to do?
    @animals_chased = []
  end

  # attr_reader :animals_chased (accessor, writer, etc are similar)
  # simply defines this method:
  def animals_chased
    @animals_chased
  end

  def bark
    "woof!" # <-- Bark method will return this value (the string "woof!")
  end

  # puts -> "side effect"

  def chase_animal(animal) # <-- method argument behaves like a local variable
    puts "So far, these are the animals I have chased: #{@animals_chased}"

    @animals_chased << animal

    # do all kinds of stuff up here
    #one
    # two
    # three

    "woof! chasing #{animal}"
  end
end

fido = Dog.new
spot = Dog.new


fido.bark

class Car

  attr_accessor :color
  attr_accessor :wheel_count
  # allow me to read AND set an instance variable from
  # outside of this object

  # def color=(new_color)
  #   @color = new_color
  # end
  # def color
  #   @color
  # end

  def initialize
    @started = false # default --> car is NOT started by default
  end

  def start
    if !@started
      @started = true
    else
      "BZZT! Nice try, though."
    end
  end

  def horn
    "BEEEP!"
  end

  def drive(distance)
    "I'm driving #{distance} miles"
  end

  def report_color
    # "I am #{@color}" #  <-- will look up the ivar directly
    "I am #{color}" #  <-- will look up the method color which we defined via attr_accessor
  end
end

my_car = Car.new
puts my_car.horn
puts my_car.drive(12)

my_car.color = "purple" # <-- thanks to attr_accessor

puts my_car.report_color

my_car.wheel_count = 18

puts "This sweet ride is sitting on #{my_car.wheel_count} wheels"

my_second_car = Car.new

my_second_car.wheel_count = 2
puts "This sweet ride is sitting on #{my_second_car.wheel_count} wheels"

puts my_second_car.start
puts my_second_car.start