simple_class_example.rb

class Car
  attr_accessor :colour
  attr_reader :make

  def initialize(make, colour)
    @make = make
    @colour = colour
  end

  def car_start
    "Vrooom!"
  end
end

holden = Car.new("Holden", "Red")
ford = Car.new("Ford", "Blue")
bmw = Car.new("BMW", "Silver")

p holden.make
p ford.make

p bmw.colour

bmw.colour = "Gold"

p bmw.colour

p bmw.car_start
p holden.car_start

p holden