如何修复这个基本程序？ Java do-while 循环

Question

我正在写这个猜谜游戏，它允许用户输入一个数字作为最大数字。

然后随机生成器将选择一个介于 1 和用户输入的最大数字之间的数字。

会保存并显示高猜数和低猜数

我遇到的问题是循环程序和验证。

我无法让程序在用户输入错误输入（即不是整数）后循环返回。

我希望它在显示错误消息后循环返回以进行另一次猜测。

我正在使用 try/catch 但在出现错误消息后程序不允许用户输入另一个数字以继续游戏。

import java.util.ArrayList;
import java.util.Random;
import javax.swing.JOptionPane;

public class guessinggame { // class name

    public static void main(String[] args) { // main method

        String smax = JOptionPane.showInputDialog("Enter your maximum number for the Guessing Game:");
        int max = Integer.parseInt(smax);

        do {
            if (max > 10000) {
                JOptionPane.showMessageDialog(null, "Oh no! Please keep your number less than 10,000.");
                smax = JOptionPane.showInputDialog("Enter your maximum number for the Guessing Game:");
                max = Integer.parseInt(smax);
            }
        } while (max > 10000);

        int answer, guess = 0, lowcount = 0, highcount = 0, game;
        String sguess;
        Random generator = new Random();
        answer = generator.nextInt(max) + 1;

        ArrayList<String> buttonChoices = new ArrayList<>(); // list of string arrays called buttonChoices 
        buttonChoices.add("1-" + max + " Guessing Game");

        Object[] buttons = buttonChoices.toArray(); // turning the string arrays into objects called buttons

        game = JOptionPane.showOptionDialog(null, "Play or Quit?", "Guessing Game",
                JOptionPane.PLAIN_MESSAGE, JOptionPane.QUESTION_MESSAGE,
                null, buttons, buttonChoices.get(0));

        do {
            sguess = JOptionPane.showInputDialog("I am thinking of a number between 1 and " + max + ". Have a guess:");
            try {
                guess = Integer.parseInt(sguess);
            } catch (Exception nfe) {
                JOptionPane.showMessageDialog(null, "That was not a number! ");
            }

            if (guess < answer) {
                JOptionPane.showMessageDialog(null, "That is too LOW!");
                lowcount++;

            } else if (guess > answer) {
                JOptionPane.showMessageDialog(null, "That is too HIGH!");
                highcount++;
            }

        } while (guess != answer);
        JOptionPane.showMessageDialog(null, "Well Done!" + "\n---------------" + "\nThe answer was " + answer + "\nLow Guesses: " + lowcount
                + "\nHigh Guesses: " + highcount + "\n\nOverall you guessed: " + (lowcount + highcount) + " Times");

        System.exit(0);
    }
}

Answer 1

运行它在我的机器上，并且循环正常。虽然它坏了； guess默认为0，你继续执行异常后的代码。如果碰巧随机数为 0，程序将退出，因为它是正确的猜测。假设你的机器上发生了这样的事情？

您还没有在初始 "what's your max number" 位周围放置保护逻辑。

Answer 2

在 try catch 中使用 continue;。

代码会像

        try {
                guess = Integer.parseInt(sguess);
            } catch (Exception nfe) {
                JOptionPane.showMessageDialog(null, "That was not a number! ");
                continue;
            }

Answer 3

虽然我看不到您描述的问题，但我建议您将比较代码放在 try 块中，这样您就可以确定在进行任何比较之前正确设置了 guess 变量：

        try {
            guess = Integer.parseInt(sguess);
            if (guess < answer) {
                JOptionPane.showMessageDialog(null, "That is too LOW!");
                lowcount++;

            } else if (guess > answer) {
                JOptionPane.showMessageDialog(null, "That is too HIGH!");
                highcount++;
            }
        } catch (Exception nfe) {
            JOptionPane.showMessageDialog(null, "That was not a number! ");
        }

如何修复这个基本程序？ Java do-while 循环

How to fix this basic program? Java do-while loop

java

loops

try-catch

joptionpane

do-while