C - malloc array in function and then access array from outside

Question

Here is how I malloc an int var and then access this var outside of the function

int f1(int ** b) {
  *b = malloc(sizeof(int)); 
  **b = 5;
}

int main() {
          


        

Answer 1

(untested, but I believe it'll work)

int f1(int ** b) {
  *b = malloc(sizeof(int)*4); 

  (*b)[0] = 5;
  (*b)[1] = 6;
  (*b)[2] = 7;
  (*b)[3] = 8;
}

int main() {
  int * a;
  f1(&a);
  printf("%d %d %d %d\n", a[0], a[1], a[2], a[3]); // should be "5 6 7 8"
  // keep it clean : 
  free(a);
  return 0;
}