Function SumDigits Learn programming Java

public class Main
{
	public static int SumDigits(int n)
	{
		String number = String.valueOf(n);

		int sum = 0;

		for (int i = 0; i < number.length(); i++)
		{
			sum += Integer.parseInt(number.substring(i, i + 1));
		}

		return sum;
	}

	public static void main(String[] args)
	{
		System.out.println(SumDigits(123));
	}
}