public class CountDigits {
    public int countDigitsIterativ(int n) {
        int count = 0;
        while (n != 0) {
            n /= 10;
            count++;
        }
        return count;
    }

    public int countDigitsRekursiv(int n) {
        if (n != 0) {
            n /= 10;
            return 1 + countDigitsRekursiv(n);
        }
        return 0;
    }
}