Question

我正在尝试将二维数组传递给numOfStudents函数，但Visual Studio给出了一个错误说：

没有重载“numOfStudents”的实例与参数列表匹配

我一直在尝试一切，但我找不到解决方案。

#include <stdio.h>
#include <cstring>

//Prototypes
int unsigned numOfStudents(char **namesArray, int *, FILE *);
void printArrays(char **namesArray, int *marksArray, int loopCounter);
int unsigned minMark(int);
int unsigned maxMark(int);
int unsigned averageMark(int);

//Two constants used later to create array of characters
const int MAX_SIZE = 10;
const int NAME_LENGTH = 30;

int main()
{
    // Declaring array which will hold all names from file
    char namesArray[MAX_SIZE][NAME_LENGTH];
    int unsigned studentNumber = 0;
    int loopCounter = 0;
    int marksArray[MAX_SIZE]; //Array will hold the marks of students, it needs to be same size as the previous array

    FILE *file; //creating pointer to a file
    file = fopen("names.txt", "r"); //telling the pointer where the file is and how to access it

    loopCounter = numOfStudents(namesArray, marksArray, file);
    //System pause - will hold console window open
    getchar();
    return 0;
}

int unsigned numOfStudents(int *marksArray, char **namesArray, FILE *file)
{
    char tempArrayName[50]; //Temporary array to hold names
    char tempArrayLastName[50]; //Temporary array to hold last names
    int i = 0; //Counter
    bool stop = false;

    if(file == NULL)
    {
        printf("\nFile has been not opened correctly\n");
    }
    else
    {
        while (stop == false)
        {
            //Reading the file in order to get 3 separate lines which are assumed as a single record of one student
            fscanf(file, "%s\n%s\n%d", tempArrayName, tempArrayLastName, &marksArray[i]);
            //Following lines are compying strings from temp arrays into main array and adding a space for better readability
            strcpy(namesArray[i], tempArrayName);
            strcat(namesArray[i], " ");
            strcat(namesArray[i], tempArrayLastName);
            //Chcecking if the sentinel value was read in order to stop the loop
            stop = strcmp(tempArrayName, "****");
            i++; //adding the counter
            //Checking if file is too big, before program will crash with an internal error
            if (i == MAX_SIZE)
            {
                printf("ERROR!!! FILE TOO BIG TO READ!");
                stop == true;
            }
        }
    }

    return i;
}

Answer 1

使用此参数列表声明numOfStudents：

int unsigned numOfStudents(char **namesArray, int *, FILE *);

但是你用不同的参数列表定义它：

int unsigned numOfStudents(int *marksArray, char **namesArray, FILE *file)

请注意，您的声明将char**作为第一个参数，但您的定义将其作为第二个参数（与int*相反）。参数的排序非常重要，必须完全匹配，因此您需要更改定义以匹配声明：

int unsigned numOfStudents(char **namesArray, int *marksArray, FILE *file)
{
....
}

Answer 2

2D数组可以是pain to pass around，为什么不使用std::string并传递它们的数组（或引用std::vector）？

Answer 3

int unsigned numOfStudents(char **namesArray, int *, FILE *);  // declaration

int unsigned numOfStudents(int *marksArray, char **namesArray, FILE *file) // definition

检查每个参数的顺序。定义的第二个参数实际上是声明的第一个参数。如果你纠正订单，你应该很好

Answer 4

您已将函数numOfStudents的签名定义为：

int unsigned numOfStudents(char **namesArray, int *, FILE *);

并且您将该函数声明为：

int unsigned numOfStudents(int *marksArray, char **namesArray, FILE *file)
{

      ---*** Your Code Here ***---

}

这是函数签名的“调用参数序列”和函数声明应该与传递参数相同的问题。所以应该是这样的：

int unsigned numOfStudents(char **namesArray, int *marksArray, FILE *file)
{

      ---*** Your Code Here ***---

}

在C ++中将二维数组传递给函数

4 个答案: