string类在c++中使得程序员对于字符串的操作更加方便，今天就来编写自己的MyString类。(The string class makes it easier for programmers to manipulate strings in c ++, and to write your own MyString class today.)

实现智能关机，帮助检测试人员测试COMS SENSER测试(Realize intelligent shutdown, help test staff test COMS SENSER test)

本来是想全部实现c++中string类的功能 但是只实现了string类的部分功能(Implementing part of the functions of the string class)