局部变量不会初始化（Java）

Question

I'm trying to write a simple dice rolling game, where if the dice match, it's a win, if they are one number apart, it's a tie (junker), and if they satisfy neither of those conditions, it's a loss.

I'm using a do while loop, and can't seem to get the local variables to initialize:

import java.util.Scanner;

public class Program06 
{
public static void main(String[] args)
{
    Scanner stdIn = new Scanner(System.in);
    String response = "k";

    int d1 = 1;
    int d2;
    int win;
    int lose;
    int junker;

    System.out.println("Welcome to Computer Dice");
    System.out.println("---------------------------");
    System.out.println("\nYou will first roll your dice");

    System.out.println("Next the outcome of your roll will be determined:");

    System.out.println("Any pair and you Win");
    System.out.println("Anything else and you Lose");
    System.out.println("\n----------------------------");

    System.out.println();

    do
    {

    System.out.println("Player");
    System.out.println("----------");

    d1 = (int)(Math.random() * 6) + 1;
    d2 = (int)(Math.random() * 6) + 1;

    if (d1 == d2)
        ++win;
    else if
        (d1 == d2 +1 || d1 == d2 -1)
        ++junker;
    else
        ++lose;

    System.out.print("Do you wish to play again? [y, n]: ");
    response = stdIn.next();

    } while (d1 == -1);
    stdIn.close();
    }
}

I've tried inserting brackets with the if else statements but that hasn't helped.

Answer 1

You don't set initial values for win , lose , or junker , yet you're trying to increment them.

You must set them to 0 to begin with.

Answer 2

Your win , lose , junker fields are local variables which means they are not initialized automatically like instance variables. You have to initialize them manually.

Answer 3

Instead of:

int win;
int lose;
int junker;

Initialize these local variables like this:

int win = 0;
int lose = 0;
int junker = 0;

This is because local variables are not initialized by default (unlike fields).

Answer 4

It's showing this error for win, junker and lose which have no value assigned to them yet. Either set them to zero or set them at the class level as static variables which automatically sets them to zero.

Answer 5

变量可能与do while循环“分离”，这意味着您应该在循环内部初始化它们。