RecursionDigitSum

using System;
class Exercise1
{

   public static int DigitSum(int n1)
{
    if(n1 == 0) {
        return 0;
    } else {
        return ((n1 % 10) + DigitSum(n1 / 10));//calling the function DigitSum itself
    }

}

public static int test(int n1)
{
    int sum;

    sum = DigitSum(n1);//call the function for calculation

    return sum;
}
}