虚拟超市购物

1、商品类包含属性名称，商品现有数量，以及纯虚函数：输出函数、

增加商品函数、卖出函数、按照名称查找函数等。

2、从商品类中派生日常用品类，食品类，家电类。其中，食品类商品和日常用品类拥有保质期属性，家电类商品拥有颜色属性。由输出函数来具体显示各类商品的名称、基本属性和现有数量。-1 virtual supermarket shopping, goods class contains the attribute name, the number of products available, and the pure virtual function: output function, increase the function of goods, selling function, search function by name and so on. 2, derived from the commodity daily necessities, food, home appliances category. Among them, food products and daily necessities has a shelf life of property classes, home appliance products with the color attribute. Shown by the output function to the specific names of all kinds of goods, basic properties and the existing number.