用类定义一个双向链表，并定义双向链表的排序插入，删除和输出操作的成员函数，可以实现依据姓名查找结点及修改结点数据的功能，把记录以通讯录形式保存在磁盘上。,Class definition with a two-way linked list, and define the order of two-way linked list insert, delete, and member functions of the output operation can be achieved based on the names to find and modify node data node to the form of records to address book stored in the disk .