How to know the size of array [] in C

int sz, array[] = {1,2,3,4,5};

sz = sizeof(array)/sizeof(int);

for(i = 0;i < sz; i++ ) {..................}

const char *const canvas_type[6] =
  {
    "A", "B", "C", "D", "E", "F"
  };

  int sz = sizeof(canvas_type)/sizeof(char*);

With 64 bit AMD machine, the above mathod has a compiled problem.