public void part4() {
        Scanner scan = new Scanner(System.in);
        System.out.print("Enter formating string: ");
        String doubleFormatingValue = scan.next();
        System.out.print("Enter floating point number: ");
        String doubleNumber = scan.next();
        if (!TextIO.isDouble(doubleNumber)) {
            System.err.println("Unsupported input value");
        } else {
            double d = Double.parseDouble(doubleNumber);
            System.out.println("Formated number: " + String.format(doubleFormatingValue, d));
        }
    }

    public void part5() {
        int biggerNumber = 0, smallerNumber = 0;
        Scanner scan = new Scanner(System.in);
        System.out.println("Enter two integers");
        String s1 = scan.next();
        String s2 = scan.next();
        if ((!TextIO.isInteger(s1)) || (!TextIO.isInteger(s2))) {
            System.err.println("Unsupported input value");
        } else {
            int firstNumber = Integer.parseInt(s1);
            int secondNumber = Integer.parseInt(s2);

            if (firstNumber >= -100 && firstNumber <= 100 && secondNumber >= -100 && secondNumber <= 100) {
                if (firstNumber > secondNumber) {
                    biggerNumber = firstNumber;
                    smallerNumber = secondNumber;
                } else {
                    smallerNumber = firstNumber;
                    biggerNumber = secondNumber;
                }
                System.out.println("Min: " + smallerNumber + " max: " + biggerNumber);
            } else {
                System.err.println("An input value out of range");
            }
        }
    }

    public void start(String[] args) {
        final int PART = 4;
        int pocet = args.length; //pocet argumentov
        int part = Integer.parseInt(args[3]);

        switch (PART) {
            case 1:
                part1();
                break;
            case 2:
                part2();
                break;
            case 3:
                part3(args);
                break;
            case 4:
                part4();
                break;
            case 5:
                part5();
                break;
        }
    }
}