Question

所以，我一直遇到一个问题，我的程序试图读取一个文件，“LineUp.txt”，我组织文件的名称按字母顺序排列，但它不会读取多个名称，它只是一遍又一遍地读取名字。我正在使用for循环，而不是while循环，这在其他问题中我没有见过。我很感激帮助！这是代码：

#include <iostream>
#include <string>
#include <fstream>
using namespace std;

int main (){

    ifstream myFile;
    string name, front, back;
    int numOfStudents, i;

    myFile.open("LineUp.txt");

    if(!myFile)
        cout << "File not found";

    cout << "Please enter the number of students: ";
    cin >> numOfStudents;

    myFile >> name;

    front = name;

    back = name;

    while(myFile >> name){

        if(name < front)
            front = name;

        if(name > back)
            back = name;

    }

    for(i = 0; i < numOfStudents; i++){

        myFile >> name;

        cout << name << endl;

    }



    return 0;
}

Answer 1

while循环会耗尽您的输入流。

如果您想再次从文件中读取，则必须创建新的输入流。

myFile.open("LineUp.txt");

if(!myFile)
    cout << "File not found";

cout << "Please enter the number of students: ";
cin >> numOfStudents;

myFile >> name;

front = name;

back = name;

while(myFile >> name){

    if(name < front)
        front = name;

    if(name > back)
        back = name;

}

ifstream myFile2("LineUp.txt"); //Create a new stream

for(i = 0; i < numOfStudents; i++){

    myFile2 >> name;

    cout << name << endl;

}

如何使用for循环使文件移动到下一行

1 个答案: