/*---------------------

作者：dongfanglanyi

来源：CSDN

原文：https://blog.csdn.net/dongfanglanyi/article/details/82355982

版权声明：本文为博主原创文章，转载请附上博文链接！

*/

#include <stdio.h>

#include <iostream>

#include <string.h>

using namespace std;

int main(int argc, char *argv[])

{

string str = "hello world!";

char *buff;

const char * cstr = str.data();

const char *cstr2 = str.c_str();

//string::npos是机器上最大的正整数，常用来表示string的结束位置

size_t length = str.copy(buff,string::npos,0);

buff[length] = '\0';

for(int i =0; str[i]!='\0'; i++)

cout << str[i];

cout <<"data():" << cstr << endl;

cout << "c_str():" << cstr2 << endl;

cout << "copy():" << buff << endl;

str = "chinese";

cout <<"data():" << cstr << endl;

cout << "c_str():" << cstr2 << endl;

cout << "copy():" << buff << endl;

return 0;

}