C/C++ 字串接字串或int 範例

如何把 int 轉成字串可以參考站內文：
C and C++ 字串(string) 轉 數字，數字 轉 字串(string) 綜合整理

/*****************************************************************
Name : string append
Date : 2018/01/29
By   : CharlotteHonG
Final: 2018/01/29
*****************************************************************/
#include <iostream>
#include <string>
#include <cstring>
using namespace std;

//================================================================
int main(int argc, char const *argv[]){
    char str[]="ABC\0";

    // c++ style
    int num = 7;
    cout << str << "DEF=\0" << num << endl;
    cout << string(str)+"DEF=\0"+to_string(num) << endl;

    // c style
    char buf[9];
    strcpy(buf, str);
    strcat(buf, "DEF=\0"); 
    char buf2[2];
    sprintf(buf2,"%d", 7);
    strcat(buf, buf2); 
    printf("%s\n", buf);
    return 0;
}
//================================================================

​