computer_class.rb

class Computer
  def initialize(brand)
    @brand = brand
    @power = false
  end

  def power_on
    @power = true
  end

  def power_off
    @power = false
  end

  def power
    @power
  end

  def brand=(computer_brand)
    @brand = computer_brand
  end

  def brand
    @brand
  end
end

macbook_air = Computer.new
macbook_air.power_on
macbook_air.brand = "Apple"
p macbook_air
macbook_air.power_off
p macbook_air.power