Question

So im making everyone’s fun game “Rock, Paper, Scissors” I got everything working, except having the while loop repeat 3 time before stopping. Well it does repeat 3 times and stops, but the 2nd and 3rd repeat the variables don’t change. Take a look at the code and tell me what I’m doing wrong.
**UPDATE: Now that I have everything working how do I get this “Q” string to terminate the loop?

import java.util.Scanner;
import java.util.Random;

public class RockPaperScissors
{

    /**
     * (Insert a brief description that describes the purpose of this method)
     * 
     * @param args
     */
    public static void main(String[] args)
    {
        int compint;
        String usermove = "";
        String compmove = "";
        String winner = "";
        int count = 0;


        Scanner in = new Scanner(System.in);
        Random gen = new Random();

        System.out.println("Enter Rock(1), Paper(2), Scissors(3) {Q to quit]: ");
        int input = in.nextInt();       

        while (count < 3)
        {
            compint = gen.nextInt(3) + 1;

            if (input == 1)
            {
                usermove = "Rock";
            }
            else if (input == 2)
            {
                usermove = "Paper";
            }
            else if (input == 3)
            {
                usermove = "Scissors";
            }

            if (compint == 1)
            {
                compmove = "Rock";
            }
            else if (compint == 2)
            {
                compmove = "Paper";
            }
            else if (compint == 3)
            {
                compmove = "Scissors";
            }

            if (compint == input)
            {
                winner = "TIE";
            }
            else if (compint == 1 && input == 3)
            {
                winner = "COMPUTER";
            }
            else if (compint == 2 && input == 1)
            {
                winner = "COMPUTER";
            }
            else if (compint == 3 && input == 2)
            {
                winner = "COMPUTER";
            }
            else
            {
                winner = "USER";
            }

            System.out.print("Computer: " + compmove + " | ");
            System.out.print("You: " + usermove + " | ");
            System.out.println("Winner: " + winner);
            System.out.println();
            System.out.println("Enter Rock(1), Paper(2), Scissors(3) {Q to quit]: ");
            input = in.nextInt();
            count++;

        }
    }
}

Output:

Enter Rock(1), Paper(2), Scissors(3) {Q to quit]: 
1
Computer: Scissors | You: Rock | Winner: USER

Enter Rock(1), Paper(2), Scissors(3) {Q to quit]: 
2
Computer: Rock | You: Paper | Winner: USER

Enter Rock(1), Paper(2), Scissors(3) {Q to quit]: 
Q
Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Unknown Source)
    at java.util.Scanner.next(Unknown Source)
    at java.util.Scanner.nextInt(Unknown Source)
    at java.util.Scanner.nextInt(Unknown Source)
    at RockPaperScissors.main(RockPaperScissors.java:102)

Answer 1

The logic that actually does anything with the input – all those if statements – is outside of the loop. With each iteration through the look, none of that logic is not actually executed. It all just happens first. Try this instead:

for (int count=0; count < 3; count++)
{
    int input = in.nextInt();
    int compint = gen.nextInt(3) + 1;

    // all the if statements and printing here
}

---

**UPDATE: Now that I have everything working how do I get this “Q” string to terminate the loop?

You’re getting an InputMismatchException when typing Q but the code calls Scanner#nextInt(). The docs are pretty clear on what the problem is:

Thrown by a Scanner to indicate that the token retrieved does not match the pattern for the expected type, or that the token is out of range for the expected type.

It’s basically the Scanner‘s way of telling you “you asked for an int but the next token isn’t one.” You can add an additional check before the nextInt() calls, using Scanner#hasNextInt(), to verify that the next token actually is an int. If it’s not an int, then you can plan on parsing it just as a string.

So instead of this:

input = in.nextInt();

Do something like this:

if (in.hasNextInt())
{
    input = in.nextInt();
} else if (in.hasNext("Q")) {
    // quit
}