#include<iostream>
/*To get the last element of the array we first get the size 
    of the array by using sizeof().  Unfortunately, this gives 
    us the size of the array in bytes.  To fix this, we divide
    the size (in bytes) by the size of the data type in the array.
    In our case, this would be int, so we divide sizeof(array) 
    by sizeof(int).  Since arrays  start from 0 and not 1 we 
    subtract one to get the last element.
    -yegor*/
int array[5] = { 1, 2, 3, 4, 5 };
printf("Last Element of Array: %d", array[(sizeof(array)/sizeof(int))-1]);

int arr[10];
int len = sizeof(arr) / sizeof(arr[0]);