c - Typedef 结构并传递给函数

Question

我正在尝试声明一个 typedef 结构数组，然后将其传递给一个函数，但我遇到了错误，因为我不确定语法是否正确，将不胜感激。这是我的代码:

#include <stdlib.h>
#include <stdio.h>

#define MAX_COURSES 50

typedef struct courses      //creating struct for course info
{
    int Course_Count;
    int Course_ID;
    char Course_Name[40];
}course;    

void Add_Course(course , int *);

int main()
{
    course cors[MAX_COURSES];
    int cors_count = 0;

    Add_Course(cors, &cors_count);
    return 0;
}

void Add_Course(course cors, int *cors_count)
{
    printf("Enter a Course ID: ");  //prompting for info
    scanf("%d%*c", cors.Course_ID);
    printf("Enter the name of the Course: ");
    scanf("%s%*c", cors.Course_Name);

    cors_count++;   //adding to count

    printf("%p\n", cors_count);
    return;
}

我得到的错误是:

error: incompatible type for argument 1 of ‘Add_Course’

test2.c:28:6: note: expected ‘course’ but argument is of type ‘struct course *’

test2.c: In function ‘Add_Course’:

test2.c:81:2: warning: format ‘%d’ expects argument of type ‘int *’, but argument 2 has type ‘int’ [-Wformat]

任何帮助将不胜感激

Answer 1

你正在将一个数组传递给一个需要struct course实例的函数，像这样尝试

Add_Course(cors[cors_count], &cors_count);

但是之后它只会在Add_Course中被修改所以你需要

void Add_Course(course *cors, int *cors_count)
{
    printf("Enter a Course ID: ");
    /* this was wrong, pass the address of `Course_ID' */
    scanf("%d%*c", &cors->Course_ID);
    /* Also, check the return value from `scanf' */
    printf("Enter the name of the Course: ");
    scanf("%s%*c", cors->Course_Name);

    /* You need to dereference the pointer here */
    (*cors_count)++; /* it was only incrementing the pointer */

    return;
}

现在你可以

for (int index = 0 ; index < MAX_COURSES ; ++index)
    Add_Course(&cors[index], &cors_count);

虽然在这种情况下 cors_count 将等于 MAX_COURSES - 1，但它毕竟可能有用。