ej2.rb

class Product
  attr_reader :code, :name, :price

  def initialize(code, name, price)
    @code = code
    @name = name
    @price = price
  end
end


class Purchase
  def initialize
    @lista = Array.new
    @total = 0
  end

  def add(item)
    @lista << item
  end

  def delete(anItem)
    @lista = @lista.select{ |item| item.code != anItem.code }
  end

  def total
    if total == 0
      @lista.inject(0) { |sum, item| sum + item.price }
    end

    return @total
  end

end