来自difftime()的手册页:
double difftime(time_t time1, time_t time0); 该difftime()函数返回时间time1和时间之间经过的秒数time0,表示为a double.
double difftime(time_t time1, time_t time0);
该difftime()函数返回时间time1和时间之间经过的秒数time0,表示为a double.
difftime()
time1
time0
double
由于"秒数"不需要浮点数,为什么这个函数会返回double?