php 购物车功能 使用session 开发，session使用方便，速度快。这原来是一个国外的朋友开发的类，我只是在这基础上增加了应用部分，也可以在此基础上做更多的扩展，欢迎朋友们使用。-php function using the session to Cart Development, session easy to use, fast. This was a friend abroad to develop the class, I just add in this part of the application can also be done on the basis of more extended, welcome friends to use.