#pragma warning(disable:4996)

 #include "stdafx.h"

 #include<iostream>

 #include<string>

 #pragma warning(disable:4996)   //debug

 using std::cout;

 using std::endl;

 class mystring

 {

 public:

     mystring(char* data = nullptr);

     mystring(const mystring & str);

     ~mystring();

     mystring & operator=(const mystring & s);

     void print();

 private:

     char* m_data;

 };

 mystring::mystring(char* data)

 {

     if (data == nullptr)

     {

         data = new char[];

         data[] = '\0';

     }

     else

     {

         int length = strlen(data);

         m_data = new char[(length + )];

         strcpy(m_data, data);

     }

 }

 mystring::mystring(const  mystring & s)

 {

     int length = strlen(s.m_data);

     m_data = new char[(length + )];

     strcpy(m_data, s.m_data);

 }

 mystring::~mystring()

 {

     delete[]m_data;

 }

 mystring & mystring::operator=(const mystring & s)

 {

     if (this == &s)

         return *this;

     delete[]m_data;

     m_data = nullptr;

     m_data = new char[strlen(s.m_data) + ];

     strcpy(m_data, s.m_data);

 }

 void mystring::print()

 {

     cout<<("s%", m_data)<<endl;

 }

 int main()

 {

     mystring kk = "hello";

     mystring nn;

     nn = kk;

     kk.print();

     nn.print();

     system("pause");

     return ;

 }