C++ 如何修复'；未在此范围内声明ARRSSTUD'；C+中的错误+；

我目前正在编写一个程序，它将在4列（ID、名字、姓氏和GPA）中显示学生记录，按升序对他们的记录进行排序，并从排序后的学生记录中将每个GPA重置为0.0

学生记录存储在一个名为“StudentInfo.txt”的文本文件中

我遇到的问题是在

ifstream inputFile

之前声明一个结构数组。在第42、53和68行显示一条错误消息，显示“ARRSSTUD未在此范围内声明”

我尝试实现了

studentInfo**arrStud[SIZE]

和

studentInfo*arrStud[SIZE]

，但没有成功，出现了另一堆错误

如果有人能帮我解决这个问题，我将不胜感激

我当前的代码：

#include <string>
#include <iomanip>
#include <fstream>
#include <iostream>

using namespace std;

struct studentInfo
{
    int ID;
    string firstName;
    string lastName;
    double GPA;
};

const int SIZE = 100;
void display(/*parameter*/,int);
void resetGPA(studentInfo **, int);
void sortStud(studentInfo **, int);

int main()
{
    int counter = 0;
    int ID;
    string firstName;
    string lastName;
    double GPA;

    // Declare arrStud here...

    ifstream inputFile;

    inputFile.open("StudentInfo.txt");
    if (inputFile.is_open())
    {
        cout << "ID:" << setw(15) << "Name:" << setw(14) << "GPA:" << endl;
        cout << "-------------------------------------------" << endl;

        while(!inputFile.eof())
        {
            inputFile >> ID >> firstName >> lastName >> GPA;
            arrStud[counter] = new studentInfo;

            arrStud[counter]->ID = ID;
            arrStud[counter]->firstName = firstName;
            arrStud[counter]->lastName = lastName;
            arrStud[counter]->GPA = GPA;

            counter++;
        }

        for (int i = 0; i < counter; i++)
        cout << i << arrStud[i]->ID
             << setw(8) << arrStud[i]->firstName
             << setw(10) << arrStud[i]->lastName
             << setw(8) << arrStud[i]->GPA
             << endl;
        cout << "-------------------------------------------" << endl;
        cout << endl;

        inputFile.close();
    }
    else
        cout << "File cannot be opened.";
        inputFile.close();


    display(arrStud, counter);
    cout << endl;
    cout << "Sorting Students by ID..." << endl;
    cout << endl;
    sortStud(arrStud, ID);
    cout << endl;
    cout << "Resetting GPA Data..." << endl;
    cout << endl;
    resetGPA(arrStud, GPA);
}

void display()
{

}

void resetGPA(studentInfo** students, int numStu)
{

    for (int i = 0; i < numStu; i++)
    {
        students[i]->GPA = 0.0;
    }

}

void sortStud(studentInfo** students, int numStu)
{
    int lowestIDIndex; //holds the index in the array students of the student with the lowest ID

    for (int i = 0; i < numStu; i ++)
    {
        lowestIDIndex = i; //always start with lowest ID being first student

        for (int j = i; j < numStu; j++) //j is equal to i so that you don't search the already sorted elements, which are less than i
        {
            if (students[j]->ID < students[lowestIDIndex]->ID) //search for the lowest ID
            {
                lowestIDIndex = j; //keep track of the lowest ID
            }
        }
            //switch the lowest element with the front-most element
            studentInfo* tempStuPtr = students[i];
            students[i] = students[lowestIDIndex];
            students[lowestIDIndex] = tempStuPtr;
    }
}

---

您的代码中没有声明任何内容！在

main（）

函数的顶部附近，您需要这样的内容（或者您可以将其作为全局变量，比如说在

main

的定义之前）：

然后，在

main

结束时（或接近结束时），您需要释放通过

new

调用创建的内存：

for (int c = 0; c < counter; ++c) delete arrStud[c];

---

您的代码中还有许多其他错误！如果为下一次生成启用编译器警告，这些警告将变得清晰。

ID:          Name:          GPA:
-----------------------------------
123456789    John   Johnson     3.5
512434990    Mary   Jackson     3.9
342432444   Peter     Young     2.3
470068625     Jim       Lee     2.9
234324324   Tammy    Gaddis     3.1
121219000   Ester    Schwab     2.7
-----------------------------------


Sorting Students by ID...

ID:          Name:          GPA:
-----------------------------------
512434990    Mary   Jackson     3.9
123456789    John   Johnson     3.5
234324324   Tammy    Gaddis     3.1
470068625     Jim       Lee     2.9
121219000   Ester    Schwab     2.7
342432444   Peter     Young     2.3
-----------------------------------


Resetting GPA Data...

ID:          Name:          GPA:
-----------------------------------
512434990    Mary   Jackson     0.0
123456789    John   Johnson     0.0
234324324   Tammy    Gaddis     0.0
470068625     Jim       Lee     0.0
121219000   Ester    Schwab     0.0
342432444   Peter     Young     0.0
-----------------------------------

studentInfo* arrStd[SIZE];

for (int c = 0; c < counter; ++c) delete arrStud[c];

void display(studentInfo**, int);

void display(studentInfo** students, int numStu)
{
    // Do something here, I guess!
}