quick way to find the size of an array in C

arraySize.c

#include <stdio.h>

int main(void)
{
  int arr[] = {45, 69, 27, 3, 99, -1, 0, 948, 34, 46};
  int size = 0;

  size = sizeof(arr) / sizeof(int);

  printf("Size: %d.", size);

  return 0;
}