字符串的相加

#include <iostream>#include <string>using namespace std;int main (){string str, result_str;cout << "Enter string(Ctel+Z to endl):" << endl;while(cin >> str){if(result_str.empty()){       result_str = result_str + str;}else{result_str = result_str + ' ' + str;}}cout << "最后的字符串是：" << endl << result_str << endl;return 0;}