SUM OF THE DIGITS OF A NUMBER

#include<stdio.h>

#include<conio.h>

void main()

{

  int num,sum=0,r;

  clrscr();

  printf("\nEnter a number:");

  scanf("%d",&num);

  while(num)

  {

            r=num%10;

            num=num/10;

            sum=sum+r;

  }

   printf("sum=%d",sum);

  getch();

}