在此示例中，您将学习使用用户定义的函数来计算两个时间段之间的差。
要理解此示例，您应该了解以下C语言编程主题：
#include <stdio.h>
struct TIME {
int seconds;
int minutes;
int hours;
};
void differenceBetweenTimePeriod(struct TIME t1,
struct TIME t2,
struct TIME *diff);
int main() {
struct TIME startTime, stopTime, diff;
printf("输入开始时间。 \n");
printf("输入小时、分钟和秒: ");
scanf("%d %d %d", &startTime.hours,
&startTime.minutes,
&startTime.seconds);
printf("输入停止时间。 \n");
printf("输入小时，分钟和秒: ");
scanf("%d %d %d", &stopTime.hours,
&stopTime.minutes,
&stopTime.seconds);
//开始时间和停止时间之间的时差
differenceBetweenTimePeriod(startTime, stopTime, &diff);
printf("\n时差: %d:%d:%d - ", startTime.hours,
startTime.minutes,
startTime.seconds);
printf("%d:%d:%d ", stopTime.hours,
stopTime.minutes,
stopTime.seconds);
printf("= %d:%d:%d\n", diff.hours,
diff.minutes,
diff.seconds);
return 0;
}
//计算时间段之间的差异
void differenceBetweenTimePeriod(struct TIME start,
struct TIME stop,
struct TIME *diff) {
while (stop.seconds > start.seconds) {
--start.minutes;
start.seconds += 60;
}
diff->seconds = start.seconds - stop.seconds;
while (stop.minutes > start.minutes) {
--start.hours;
start.minutes += 60;
}
diff->minutes = start.minutes - stop.minutes;
diff->hours = start.hours - stop.hours;
}输出结果
输入开始时间。
输入小时、分钟和秒: 12
34
55
输入停止时间。
输入小时，分钟和秒: 8
12
15
时差: 12:34:55 - 8:12:15 = 4:22:40在这个程序中，用户被要求输入两个时间段和这两个时期都分别存储在结构变量startTime和stopTime。
然后，函数differenceBetweenTimePeriod()计算时间段之间的差。从main()函数显示结果而不返回它（使用引用调用技术）。