Explanation for this code

Question

This loop looks like it returns only zero.

#include <stdio.h>

int main()
{
  int n, r = 0;

  printf("Enter a number to reverse\n");
  scanf("%d", &n);

  while (n != 0)
  {
    r = r * 10;
    r = r + n%10;
    n = n/10;
  }

  printf("Reverse of the number = %d\n",r);

  return 0;

Answer 1

No.
It works fine..
Input: 1234
Output: 4321