mlegy

public static String toString(int n) {
    String sign = "";
    String num = "";
    if (n == 0) {
        return "0";
    } else if (n < 0) {
        sign = "-";
        n = -n;
    }
    while (n != 0) {

mlegy

public static String format(int n) {
        String num = "" + n;
        String stringNum = "";
        int numLength = num.length();
        for (int i = 0; i < numLength; i++) {
           if ((numLength - i) % 3 == 0 && i != 0) {
                stringNum += ",";
            }
            stringNum += num.charAt(i);
            }