LeetCode-Add Digits

Given a non-negative integer num, repeatedly add all its digits until the result has only one digit.

For example:

Given num = 38, the process is like: 3 + 8 = 11, 1 + 1 = 2. Since 2 has only one digit, return it.

　　

public class Solution {
    public int addDigits(int num) {
        String numStr=Integer.toString(num);
        int total=0;
        for(int i=0; i<numStr.length(); i++){
            total=total+Character.getNumericValue(numStr.charAt(i));
        }
        if(total<10){
            return total;
        }
        else{
            return addDigits(total);
        }
    }
    
}