Can anyone help me fix this code?

Question

This program is intended to add up digits of a number until the sum is single digit. But it's not working as expected.

https://code.sololearn.com/cjHcfS9BIcuk/#

Answer 1

When you do the recursion don't forget that your function has a return value. So just calling calcSum() without actually using the result, is a waste.
Fortunately you can easily fix this in line 22.

if(sum>9){
return calcSum(sum);
}

Answer 2

And in case you want to see a maths trick:

public static int calcSum(int n) {
if(n % 9 == 0)
return 9;
else
return n % 9;
}

Answer 3

Tibor Santa
Thank you! It helped :-)

Answer 4

Nice code!
I think you should gently mark @Tibor Santa answer like a solution @Leena.