编写商品销售统计程序，商品的信息有：商品的名称，计量单位（重量或件），单价。所有商品的信息事先已存入计算机，屏幕上显示所有商品的名称，选择商品名，输入商品计量单位(如重量，件数等)，根据单价算出总价。客户一次购物可能购买多种商品，程序应计算出客户应付的钱款数 --Preparation of statistical procedures merchandise sales, merchandise information are: name of product, units of measurement (weight or parts), price. All product information into the computer beforehand, all items displayed on the screen name, select the brand name, enter the product units (such as weight, number, etc.), calculated according to unit price. Customers may purchase a variety of shopping goods, the program should calculate the number of money payable by the Client