Why does it ask for user input 2 times in a row everytime?

Question

I want the user to insert how many sticks they want to take off from the table (from 1 to 3 sticks) and then I want the program to print out the number of sticks that are left on the table after the move.

I got this far, but I just can't understand why it asks me to put the user input twice in a row before printing the result (and the second user input is the one that counts).

import java.util.Scanner;
import java.io.InputStream;

public class GameOfSticks {
    public static int sticks = 10;
    public static int sticksToTake;

    public static void main(String[] args) {
        Scanner userInputScanner = new Scanner(System.in);
        System.out.println("The number of sticks on the table is " + sticks + ".");
        System.out.print("Insert how many sticks you want to take: ");
        makeHumanMove(sticksToTake);
        System.out.println(getNumberOfSticksOnBoard());

    }

    public static int getNumberOfSticksOnBoard() {
        sticks = sticks - makeHumanMove(sticksToTake);
        return sticks;
    }

    public static int makeHumanMove(int sticksToTake) {
        Scanner userInputScanner = new Scanner(System.in);
        while (true) {
            int enteredNumber;
                try {
                    enteredNumber = userInputScanner.nextInt();
                } catch (Exception e) {
                    System.out.print("Not a number, enter a number from 1 to 3: ");
                    userInputScanner = new Scanner(System.in);
                    continue;
                }
            if (enteredNumber < 1 || enteredNumber > 3) {
                System.out.print("Incorrect number, enter a number from 1 to 3: ");
                continue;
            } else {
                sticksToTake = enteredNumber;
                return(sticksToTake);
            }
        }
    }
}

score 1 · Answer 1 · answered Feb 23 '15 at 12:24

You are calling the method makeHumanMove twice. Once in the Main method and then again in the getNumberOfSticksOnBoard method. If you remove makeHumanMove(sticksToTake); in the Main method then it works fine, as it just calls it once in the getNumberOfSticksOnBoard method.

score 0 · Answer 2 · answered Feb 23 '15 at 12:23

0

It works this way because you are calling makeHumanMove method twice. First time in main, second time in getNumberOfSticksOnBoard.

answered Feb 23 '15 at 12:23

MJ01

21
1

THANK YOU! I can't believe I couldn't realize this. – Tymu888 Feb 23 '15 at 12:26

Semih Eker · Answer 3 · 2015-02-23T12:37:42.273

Because you're calling makeHumanMove method twice. First one

 makeHumanMove(sticksToTake);

and second one inside the getNumberOfSticksOnBoard method;

 System.out.println(getNumberOfSticksOnBoard());

You can try like this(Also you can modify this, I only try toput input for once. );

public class GameOfSticks {
    public static int sticks = 10;
    public static int sticksToTake;

    public static void main(String[] args) {
        System.out.println("The number of sticks on the table is " + sticks + ".");
        System.out.print("Insert how many sticks you want to take: ");
        Scanner userInputScanner = new Scanner(System.in);
        int enteredNumber;
        while (true) {

            try {
                enteredNumber = userInputScanner.nextInt();
            } catch (NumberFormatException e) {
                System.out.print("Not a number, enter a number from 1 to 3: ");
                userInputScanner = new Scanner(System.in);
                continue;
            }
            makeHumanMove(enteredNumber);
            System.out.println(getNumberOfSticksOnBoard());
        }



    }

    public static int getNumberOfSticksOnBoard() {
        sticks = sticks - makeHumanMove(sticksToTake);
        return sticks;
    }

    public static int makeHumanMove(int enteredNumber) {

        if (enteredNumber < 1 || enteredNumber > 3) {
            System.out.print("Incorrect number, enter a number from 1 to 3: ");
        } else {
            sticksToTake = enteredNumber;
            return (sticksToTake);
        }
        return sticksToTake;

    }
}

score 0 · Answer 4 · answered Feb 23 '15 at 12:27

Just remove the line

makeHumanMove(sticksToTake);

in your main-method. On the next line

 System.out.println(getNumberOfSticksOnBoard());

inside the method

getNumberOfSticksOnBoard()

you call

makeHumanMove(sticksToTake)

again. Thats the reason you get to do an input twice in a row. The result is wrong this way as well.

Why does it ask for user input 2 times in a row everytime?

4 Answers4