Write a program in c to calculate the sum of digits.

#include<stdio.h>
int main()
{
int num,r,sum=0;
printf("Enter a number\n");
scanf("%d",&num);
while(num>0)
{
r=num%10;
sum=sum+r;
num=num/10;
}
printf("Sum of digits=%d",sum);
return 0;
}