Code snippet to find out length of an array dynamically in C

#include 
#include 

int main()
{
  int arr[] = {3,4,65,78,1,2,4};
  int arr_length = sizeof(arr)/sizeof(arr[0]); 
  
  printf("\nLength of the array is :[%d]\n\n", arr_length);
  
  getch();
  return(0);
}