Untitled

C pointer to pointer
int **p

int *p[1]

int **p;

int *p[1];

void foo()
{
    int **ptr;
    int *array[10];

    sizeof(ptr);   // just the size of the pointer
    sizeof(array); // 10 * sizeof(int *)

    // popular idiom for getting count of elements in array:
    sizeof(array)/sizeof(array[0]);
}

// this would always discard the array size,
// because the argument always decays to a pointer
size_t my_sizeof(int *p) { return sizeof(p); }

int **p

int *p[1];

int **p

int *p[1]

int **pp;   // pointer to pointer
int *ap[1]; // array of pointer

foo(ap);

pp = malloc(sizeof *pp * N); // allocate N pointers to int (type of *pp == int *)
if (pp)
{
  size_t i;
  for (i = 0; i < N; i++)
    pp[i] = ...;             // set pp[i] to point to some int value
}

ap = some_new_pointer_value();