int arr[5]; for (int i = 0; i < 5; i++) { arr[i] = i; }
int arr[5] = {1, 2, 3, 4, 5};
int arr[5]; memset(arr, 0, sizeof(arr));
int arr[5]; int *ptr = arr; for (int i = 0; i < 5; i++) { *ptr++ = i; }