Question

i find this in Pointers on C

int f[]();  /* this one is illegal */

and:

int (* f [])(); /* this one legal. */

i really want know what’s the usage of the second one.

thank you.

Answer 1

The second example is quite valid, if you use initialization block. For example:

#include <stdio.h>
int x = 0;
int a() { return x++ + 1; }
int b() { return x++ + 2; }
int c() { return x++ + 3; }

int main() 
{
  int (* abc[])() = {&a, &b, &c};
  int i = 0,
      l = sizeof(abc)/sizeof(abc[0]);
  for (; i < l; i++) { 
    printf("Give me a %d for %d!\n", (*abc[i])(), i);
  }
  return 0;
}