C++

Question

我对其中包含 ifstream 和 string 的函数有疑问。这是我的代码：

#include <iostream>
#include <time.h>
#include <iomanip>
#include <stdlib.h>
#include <fstream>
#include <string>

const int ArrayMax = 100;

int DisplayMenu();
void LoadNames();
void ReadFile(ifstream& , ifstream& ,string[],string[]);

using namespace std;

int main()
{

    ifstream FemaleFile;
    ifstream MaleFile;
    string Female[ArrayMax];
    string Male[ArrayMax];

    DisplayMenu();
    ReadFile(FemaleFile, MaleFile, Female,Male );

    return 0;
}

int DisplayMenu() //Displays menu and returns user selection
{
    //variables
    int selection;

    //Headers
    cout << "^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^" << endl;
    cout << "                Name Guess Game" << endl;
    cout << "^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^" << endl;
    cout << "        Selaect Name Category" << endl;
    cout << "                         1. Female Names" << endl;
    cout << "                         2. Male Names" << endl;
    cout << "                         3. Exit" << endl << endl;
    cout << "        Enter 1, 2  or 3:       " ;
    cin >> selection;


    while ((selection != 1) && (selection != 2) && (selection != 3) )
    {
        cout << "        Invaild choice, Please Enter 1, 2  or 3:       " ;
        cin >> selection;
    }

    return selection;
}

void LoadNames()//Loads name lists from data files into two arrays and returns array sizes. Uses ReadFile(…) function
{

    return;
}



void ReadFile(ifstream & FemaleFile ,ifstream & MaleFile, string Female[], string Male[] )//Reads the data of the received file into the received array size and returns the array size.
{


    //opening files
    FemaleFile.open("female.txt");
    MaleFile.open("male.txt");


    //Testing files
    if (!FemaleFile){
        cout << "Error, cannot open this file\n";
        return;}
    if (!MaleFile){
        cout << "Error, cannot open this file\n";
        return;}

    for (int i=0 ; i < ArrayMax; i++)
    {
        FemaleFile >> Female[i];
        cout << Female[i] << endl;
    }
        for (int i=0 ; i < ArrayMax; i++)
    {
        MaleFile >> Female[i];
        cout << Male[i] << endl;
    }


        //closeing files
        FemaleFile.close();
    MaleFile.close();

    return;
}

它总是给我这个错误：

error C2065: 'ifstream' : undeclared identifier error C2059: syntax error : ',' error C3861: 'ReadFile': identifier not found

你能帮我解决这个问题吗？

Answer 1

您在

之前输了 std::ifstream

using namespace std;

在函数声明中。

Answer 2

我认为您在函数声明之前放置了 using namespace std;。我的意思是在 int DisplayMenu(); 之前添加这个。那么就可以了。

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