Sum of digits in C#

Question

What\'s the fastest and easiest to read implementation of calculating the sum of digits?

I.e. Given the number: 17463 = 1 + 7 + 4 + 6 + 3 = 21

Answer 1

If one wants to perform specific operations like add odd numbers/even numbers only, add numbers with odd index/even index only, then following code suits best. In this example, I have added odd numbers from the input number.

using System;
                    
public class Program
{
    public static void Main()
    {
        Console.WriteLine("Please Input number");
        Console.WriteLine(GetSum(Console.ReadLine()));
    }
    
    public static int GetSum(string num){
        int summ = 0;
        for(int i=0; i < num.Length; i++){
            int currentNum;
            if(int.TryParse(num[i].ToString(),out currentNum)){
                 if(currentNum % 2 == 1){
                    summ += currentNum;
                }
            }
       } 
       return summ;
    }
}