正确的格式说明符以打印字符串

Question

我用下面的代码:

#include <stdio.h>

int main() {
    int numOfClasses;

    do{
    printf("How many classes do you have?\t");
    scanf("%d", &numOfClasses);
    }while(numOfClasses < 1);

    int count = numOfClasses;
    char nameOfClass[30];
    int numOfGrades[30];
    printf("Which classes do you have, how many grades in each class?\n");
    for(int i = 0; i < count; i++){
            scanf("%s %d", &nameOfClass[i], &numOfGrades[i]);
    }
    for(int i = 0; i < count; i++){
            printf("%s : %d\n", nameOfClass[i], numOfGrades[i]);
    }

    return 0;
}

我想让这个程序要求用户输入一个类(class)和该类(class)的成绩。稍后我会尝试输入该类(class)的每个成绩，但现在我想解决这个问题。

当我运行它时，我得到了这个错误信息:

warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘int’ [-Wformat=]
printf("%s : %d\n", nameOfClass[i], numOfGrades[i]);
       ^

Answer 1

变量 char nameOfClass[30] 应该是二维数组，如 char nameOfClass[30][30]。当您阅读类(class)名称时。所以，我把它改成了二维数组。您正在使用以下语句读取字符串数组:scanf("%s %d", &nameOfClass[i], &numOfGrades[i]); 如果你不使用二维数组，那么你的 nameOfClass 变量将只指向最后一个类名不正确。

    int count = numOfClasses;
    char nameOfClass[30][30];
    int numOfGrades[30];
    printf("Which classes do you have, how many grades in each class?\n");
    for(int i = 0; i < count; i++){
            scanf("%s %d", nameOfClass[i], &numOfGrades[i]);
    }
    for(int i = 0; i < count; i++){
            printf("%s : %d\n", nameOfClass[i], numOfGrades[i]);
    }