c - 结构: Undeclared identifiers

Question

我尝试在程序中使用结构，但收到一堆错误消息，指出 time1、time2 和 hourDif 是未声明的标识符。我以为我按照你应该的方式声明了这些结构，所以我对问题是什么感到困惑。

代码如下:

#include <stdio.h>

struct time1 {
    int seconds1;
    int minutes1;
    int hours1;
};

struct time2 {
    int seconds2;
    int minutes2;
    int hours2;
};

    int timeDif(time1, time2) {
        struct dif {
            int secDif = time2.seconds2 - time1.seconds1;
            int minDif = time2.minutes2 - time1.minutes1;
            int hourDif = time2.hours2 - time1.hours1;
        };

        printf("The difference is %d:%d:%d\n", hourDif, minDif, secDif);
    }



    int main(void) {

        printf("Enter seconds1 (ss)\n");
        scanf("%d", &time1.seconds1);

        printf("Enter minutes1 (mm)\n");
        scanf("%d", &time1.minutes1);

        printf("Enter hours1 (hh)\n");
        scanf("%d", &time1.hours1);

        printf("Enter seconds2 (ss)\n");
        scanf("%d", &time2.seconds2);

        printf("Enter minutes2 (mm)\n");
        scanf("%d", &time2.minutes2);

        printf("Enter hours2 (hh)\n");
        scanf("%d", &time2.hours2);

        timeDif(time1, time2);

    return 0;
}

Answer 1

您不需要定义三个结构体，因为它们是相同的类型——时间。您只能定义一个结构体time:

#include <stdio.h>

struct time {
    int seconds;
    int minutes;
    int hours;
};

void timeDif(struct time time1,struct time time2) {
    struct time diff= {
         time2.seconds - time1.seconds,
         time2.minutes - time1.minutes,
         time2.hours - time1.hours
    };

    printf("The difference is %d:%d:%d\n", diff.hours, diff.minutes, diff.seconds);
}

int main(void) {
    struct time time1,time2,diff;
    printf("Enter seconds1 (ss)\n");
    scanf("%d", &time1.seconds);

    printf("Enter minutes1 (mm)\n");
    scanf("%d", &time1.minutes);

    printf("Enter hours1 (hh)\n");
    scanf("%d", &time1.hours);

    printf("Enter seconds2 (ss)\n");
    scanf("%d", &time2.seconds);

    printf("Enter minutes2 (mm)\n");
    scanf("%d", &time2.minutes);

    printf("Enter hours2 (hh)\n");
    scanf("%d", &time2.hours);

    timeDif(time1, time2);

    return 0;
}