示例
#include <stdio.h>
/* increment: take number, increment it by one, and return it */
int increment(int i)
{
printf("increment %d by 1\n", i);
return i + 1;
}
/* decrement: take number, decrement it by one, and return it */
int decrement(int i)
{
printf("decrement %d by 1\n", i);
return i - 1;
}
int main(void)
{
int num = 0; /* declare number to increment */
int (*fp)(int); /* declare a function pointer */
fp = &increment; /* set function pointer to increment function */
num = (*fp)(num); /* increment num */
num = (*fp)(num); /* increment num a second time */
fp = &decrement; /* set function pointer to decrement function */
num = (*fp)(num); /* decrement num */
printf("num is now: %d\n", num);
return 0;
}
