Question

我制作了一个Java程序 - 这个程序会随机选择0到7之间的3个数字，我们必须猜测它们是什么。要查看所有数字，我想验证输入。如果用户输入的数字大于7，则会再次询问号码，同时忽略用户先前输入的号码。

代码已成功编译，但是当我运行它并选择大于7的数字时，它不会提示用户输入新号码。可能导致错误的原因是什么？我该如何解决？

import java.io.*;
import java.util.*;
import java.lang.*;

class GameHelper {
    public String getUserInput(String prompt) {
        String inputLine = null;
        System.out.print(prompt + " ");
        try {
            BufferedReader is = new BufferedReader(new InputStreamReader(System.in));
            inputLine = is.readLine();
            if(inputLine.length() == 0) {
                return null;
            }
        } catch(IOException e) {
            System.out.println("IOException: " + e);
        }
        return inputLine;
    }
}

class DotGame {
    private int PlayerGuess;
    private int NumberOfGuesses = 0;
    private int[] SelectedNumbers;
    private int NumberOfHits = 0;

    public void setPlayerGuess(String PlayerGuess1) {
        int PlayerGuess2 = Integer.parseInt(PlayerGuess1);
        if(PlayerGuess2 < 8) {
            PlayerGuess = PlayerGuess2;
        } else {
            System.out.println("enter number smaller than 8 ");
        }
    }

    public int getPlayerGuess() {
        return PlayerGuess;
    }

    public void setSelectedNumbers(int[] selected) {
        int totalArrayValue = selected[0] + selected[1] + selected[2];
        if(totalArrayValue < 21) {
            SelectedNumbers = selected;
        } else {
            System.out.println("values in array are more than they should be ");
        }
    }

    public String checkPlayerResult() {
        boolean big = true;
        NumberOfGuesses++;
        String result = "miss";

        for(int number : SelectedNumbers) {
            if(PlayerGuess == number) {
                result = "hit";
                NumberOfHits++;
                break;
            }
        }
        if(NumberOfHits == SelectedNumbers.length) {
            result = "killed";
        }
        System.out.println(result);
        return result;
    }

    public void GameScore() {
        int Score = NumberOfHits * 100 / NumberOfGuesses;

        System.out.println("Number of hits " + NumberOfHits);
        System.out.println("Number of guesses " + NumberOfGuesses);
        System.out.println("you scored " + Score);
    }
}

public class DotGameTester2 {
    public static void main(String[] args) {
        GameHelper helper = new GameHelper();
        int random = (int) (Math.random() * 7);
        int random1 = (int) (Math.random() * 7);
        int random2 = (int) (Math.random() * 7);

        DotGame game = new DotGame();
        int[] selectnumb = { random, random1, random2 };
        boolean isAlive = true;
        int numOfGuesses = 0;
        int test = 0;
        game.setSelectedNumbers(selectnumb);
        while(isAlive == true) {
            do {
                String guess = helper.getUserInput("enter a number ");
                game.setPlayerGuess(guess);
                test = game.getPlayerGuess();
            } while(test > 8);
            String result1 = game.checkPlayerResult();
            numOfGuesses++;
            if(result1 == "killed") {
                isAlive = false;
            }
        }
        System.out.println("you took " + numOfGuesses + " to guess");
        game.GameScore();
    }
}

Answer 1

while(test > 8)

应该是

while(test >= 8)

此外，当您插入大于7的数字时，仍会将之前插入的数字返回test，因此您检查的数字是否错误。

为了解决这个问题，我会像这样编辑：

PlayerGuess = PlayerGuess2;

if (PlayerGuess2 < 8) { 
    System.out.println("enter number smaller than 8 ");
}

另一种解决方案是编辑这样的代码：

do {
    game.resetGuess();
    String guess = helper.getUserInput("enter a number ");
    game.setPlayerGuess(guess);
    test = game.getPlayerGuess();
} while (test >= 8);

在PlayerGuess = 8

中实施resetGuess()

Answer 2

如果您输入11作为猜测，那么会发生什么：

String guess = helper.getUserInput("enter a number "); // guess == 11
game.setPlayerGuess(guess /* 11 */);

深入研究setPlayerGuess：

if(PlayerGuess2 < 8) {                                  // False, since 11 > 8
    PlayerGuess = PlayerGuess2;                         // skip
} else {                                                // True
    System.out.println("enter number smaller than 8 "); // This line gets executed
}

请注意如何定义private int PlayerGuess;，其中PlayerGuess默认为0。考虑到这一点......

test = game.getPlayerGuess();

这只会返回PlayerGuess 0。

现在，您在while循环中运行此操作，该循环在test > 8时执行，但此时test为0，因此循环终止

修复方法是将setPlayerGuess更改为此，因此您每次输入数字时都会设置猜测：

public void setPlayerGuess(String PlayerGuess1) {
    int PlayerGuess2 = Integer.parseInt(PlayerGuess1);
    PlayerGuess = PlayerGuess2;
    if(PlayerGuess2 >= 8) {
        System.out.println("enter number smaller than 8 ");
    }
}

现在，当您输入的数字大于7时，系统会再次提示您。

Answer 3

你的错误：如果用户的猜测大于7，game.setPlayerGuess没有设置数字becoz有一个＆＃34; if＆＃34;在方法内部。然后，你拨打game.getPlayerGuess()，你基本上会得到之前输入的有效号码。

如上所述 - 无论如何，这是一个糟糕的设计！

在我的java程序中获取一个未知的bug

3 个答案: