c++ - 'std::string' 没有名为 'front' 的成员

Question

#include <string>
#include <algorithm>
#include <iostream>

int main()
{
    string str;
    string str1;
    int h = 0;
    cin >> str;
    if (str.length() > 10)
    {
        str1 += str.front();
        h = str.length() - 2;
        string s = to_string(h);
        str1 += s;
        str1 += str.back();
        cout << str1;
    }
    else cout << str;
    return 0;
}

在 XCode 中编译，但不在 codeforces.ru/上编译

 сan't compile program.cpp:
program.cpp: In function 'int main()':
program.cpp:23:21: error: 'std::string' has no member named 'front'
program.cpp:27:29: error: 'to_string' was not declared in this scope
program.cpp:32:21: error: 'std::string' has no member named 'back'

Answer 1

一件事是 string::front 和 std::to_string 从 C++11 开始引入。您必须确保您使用的编译器支持这些新功能。