P5: OO Inheritance.rb

class Vehicle
  def initialize(args)
    @color = args[:color]
    @num_seats = args[:num_seats]
  end
 
  def drive
    @status = :driving
  end
 
  def brake
    @status = :stopped
  end
 
  def needs_gas?
    return [true,false,true,false].sample
  end
end
 
class Car < Vehicle
  @@WHEELS = 4
  def self.wheels
    @@WHEELS
  end
end
 
class Bus < Vehicle
  attr_reader :passengers
  def initialize(args)
    super
    @fare = args[:fare]
    @passengers=[]
  end
 
  def drive
    return self.brake if stop_requested?
  end
 
  def admit_passenger(passenger,money)
    @passengers << passenger if money >= @fare
  end 
 
  def stop_requested?
    return [true,false].sample
  end
end
 
class Motorbike < Vehicle
  @@WHEELS = 2
  def self.wheels
    @@WHEELS
  end
 
  def drive
    @speed = :fast
  end
 
  def weave_through_traffic
    @status = :driving_like_a_crazy_person
  end
end
 
greyhound = Bus.new(:fare => 2, :color => "red", :num_seats => 20)
 
p greyhound
puts greyhound.admit_passenger(3, 6)
puts greyhound.drive
puts greyhound.stop_requested?
puts greyhound.drive
puts greyhound.needs_gas?
 
moto = Motorbike.new(:color => "gold", :num_seats => 1)
 
puts moto.drive
puts moto.weave_through_traffic
 
supercar = Car.new(:color => "black", :num_seats => 2)
 
puts supercar.drive
puts supercar.brake
puts supercar.needs_gas?