模拟STL库中string类的功能，编写MyString类，至少实现字符串间的赋值、比较（包括>、<、=、!=）和字符串间的”＋”（连接）操作，同时能通过下面列举的形式对字符串对象进行初始化。

如：MyString str1(“I am ”),str2=“a student”

if(str1>str2) cout<<“larger\n”

if(str1<str2) cout<<“smaller\n”

if(str1==str2) cout<<“equal\n”

if(str1!=str2) cout<<“unequal\n”

MyString str3=str1+str2

-Analog STL library string class, write MyString class, at least between string assignment and comparison (>, <, =, =), and the string between the "+" operation (connection) is, at the same time through the followingenumerated in the form of a string object is initialized.

Such as: MyString str1 ("I am"), str2 = "a student"

        if (str1> str2) cout << "larger \ n"

        if (str1 <str2) cout << "smaller \ n"

        if (str1 == str2) cout << "equal \ n"

        if (str1! = str2) cout << "unequal \ n"

MyString str3 = str1 str2