即使使用#include，在Visual Studio中构建也无​​法识别getline（）或stoi（） <string> 和 <fstream> 声明

Question

I've been trying to learn C++ over the past couple of days, and ran into a problem when I was trying to use the getline() and stoi() methods in some practice code:

#include <string>
#include <fstream>
#include "stdafx.h"
#include <iostream>
using namespace std;


    int main()
    {

        string numberGuessed;
        int intNumberGuessed = 0;

        do {
            cout << "Guess a number between 1 and 10";
            getline(cin, numberGuessed);

            intNumberGuessed = (stoi(numberGuessed));
            cout << intNumberGuessed << "\n";

        } while (intNumberGuessed != 4);
        cout << "You win\n";
            return 0;



    }`

When I tried to build this code in VS 2015, the console could not identify getline or stoi as if I hadn't added #include statements for string and fstream. Is there something wrong with my code or is it something to do with VS?

Answer 1

It's something to do with VS.

Since you have

#include "stdafx.h"

I'm guessing you have precompiled headers turned on, and "stdafx.h" is the precompiled header. (That's the default name in VS)

With precompiled headers turned on, anything before the include statement for the precompiled header is ignored .

Either make sure #include "stdafx.h" is the very first thing in the file (except for comments), or turn off precompiled headers.