我如何要求用戶“再玩一次”並使用簡單的是或否問題重新運行 do while 循環？

Question

所以我添加了 yes or no 語句打印出來，但它不允許用戶輸入它。我該如何解決這個問題，我可以在 do-while 循環中嵌套 while 循環嗎？

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

public class HiLo {
    public static void main(String[] args) {
        Random random = new Random();
        Scanner input = new Scanner(System.in);
        final int MAX = 100;
        int answer = random.nextInt(MAX) + 1;
        int guess = -1;
        int numberOfGuesses = 0;
        String cont;

        System.out.println("Guess a number between 1 and " + MAX + ": ");

        do {
            while (guess != answer) {
                numberOfGuesses++;
                guess = input.nextInt();

                if (guess == 101) {
                    break;
                } else if (guess > answer) {
                    System.out.println("Too High");
                    System.out.println("\nGuess again ");
                } else if (guess < answer) {
                    System.out.println("Too Low");
                    System.out.println("\nGuess again: ");
                } else {
                    System.out.println("Correct! The number was " + answer + ".");
                    System.out.println("It took you " + numberOfGuesses + " guesses.");
                }
            }

            System.out.println("\nWould you like to play again (yes/no)?");
            cont = input.nextLine();
        } while (cont.equals("yes");

        input.close();
    }
}

Answer 1

好吧，當我查看您的循環邏輯時，它可以得到維護並像魅力一樣工作，您只需要在開始時將初始化步驟從外部移動到內部do-while循環。

這樣，在游戲的每次開始時，一切都會正常進行。

此外，在閱讀用戶選擇yes/no之前，您還忘記了 go 到下一行，因為您只閱讀int s，最后一行位於包含判決yes/no的行之前

我在在線編譯器中嘗試了這段代碼，它正在運行：

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

public class Main{

     public static void main(String []args){

        Random random = new Random();
        Scanner input = new Scanner(System.in);
        final int MAX = 100;

        System.out.println("Guess a number between 1 and " + MAX + ": ");
        String cont = new String();
        do {
            System.out.println("Let's play");
            //Initializations here
            int answer = random.nextInt(MAX) + 1;
            int guess = -1;
            int numberOfGuesses = 0;


            while (guess != answer) {
                numberOfGuesses++;
                guess = input.nextInt();

                if (guess == 101) {
                    break;
                } else if (guess > answer) {
                    System.out.println("Too High");
                    System.out.println("\nGuess again ");
                } else if (guess < answer) {
                    System.out.println("Too Low");
                    System.out.println("\nGuess again: ");
                } else {
                    System.out.println("Correct! The number was " + answer + ".");
                    System.out.println("It took you " + numberOfGuesses + " guesses.");
                }
            }

            System.out.println("\nWould you like to play again (yes/no)?");
            input.nextLine();//You have to go to the next line...
            cont = input.nextLine();
        } while (cont.equals("yes"));
        System.out.println("\nThanks for playing !");
        input.close();
     }
}

Answer 2

我會先用方法將其組織成 class。 這分解了每一段邏輯並使其更易於閱讀。

1. 開始“播放”循環
2. 在“播放”循環中，有一個“猜測”循環
3. 將“繼續”state 存儲在已知常量中
4. 僅在他們做出最大猜測次數后檢查它們是否正確。
5. 使用當前系統時間為Random object 播種

另外，我添加了一個DEBUG標志來顯示答案。

更新：該程序忽略或什至不詢問您的“是”輸入，因為您之前要求它輸入整數。 您需要通過調用nextLine來清除/刷新/重置掃描儀的緩沖區。 從 integer 切換到字符串會在緩沖區中留下一些數據。 因此，您的程序將在提示您輸入之前使用緩沖區中剩余的字符數據。

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

public class HiLo implements Runnable {
    private static boolean DEBUG = true; // Disable to not show the answer...
    private static final int MAX_NUMBER = 100;
    private static final int MAX_GUESSES = 5;
    private static final String YES = "YES";

    private final Random rand;

    public HiLo() {
        this.rand = new Random(System.currentTimeMillis());
    }

    public static void main(String[] args) {
        new Thread(new HiLo()).start();
    }

    @Override
    public void run() {
        Scanner scan = new Scanner(System.in);
        String cont = "";
        do {
            play(scan);
            System.out.print("\nWould you like to play again (yes/no)? ");
            cont = scan.nextLine();
            System.out.println();
        } while (cont.equalsIgnoreCase(YES));
        scan.close();
    }

    public void play(Scanner scan) {
        boolean correct = false;
        int numberOfGuesses = 0;
        int answer = rand.nextInt(MAX_NUMBER) + 1;

        if (DEBUG) System.out.printf("The answer is: %d%n", answer);

        System.out.printf("Guess a number between 1 and %d%n", MAX_NUMBER);

        while (numberOfGuesses < MAX_GUESSES && !correct) {
            numberOfGuesses++;
            correct = makeGuess(scan, answer, numberOfGuesses);
        }

        if (numberOfGuesses <= MAX_GUESSES && correct) {
            System.out.printf("Correct! The number was %d. It took you %d guesses.%n", answer, numberOfGuesses);
        } else {
            System.out.printf("Sorry, but you did not guess: %d", answer);
        }
        scan.nextLine(); // Reset...
    }

    public boolean makeGuess(Scanner scan, int answer, int currentGuesses) {
        System.out.print("Guess: ");
        int guess = scan.nextInt();

        if (guess == answer) {
            return true;
        }

        if (currentGuesses < MAX_GUESSES) {
            if (guess > answer) {
                System.out.print("Too High, ");
            } else {
                System.out.print("Too Low, ");
            }
        }

        return false;
    }
}

樣品 Output

The answer is: 64
Guess a number between 1 and 100
Guess: 50
Too Low, Guess: 75
Too High, Guess: 60
Too Low, Guess: 65
Too High, Guess: 64
Correct! The number was 64. It took you 5 guesses.

Would you like to play again (yes/no)? yes

The answer is: 88
Guess a number between 1 and 100
Guess: 50
Too Low, Guess: 90
Too High, Guess: 80
Too Low, Guess: 85
Too Low, Guess: 87
Sorry, but you did not guess: 88

Would you like to play again (yes/no)? no

Answer 3

所以我添加了 yes 或 no 語句打印出來，但它不允許用戶輸入它。我該如何解決這個問題，我可以在 do-while 循環中嵌套一個 while 循環嗎？

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

public class HiLo {
    public static void main(String[] args) {
        Random random = new Random();
        Scanner input = new Scanner(System.in);
        final int MAX = 100;
        int answer = random.nextInt(MAX) + 1;
        int guess = -1;
        int numberOfGuesses = 0;
        String cont;

        System.out.println("Guess a number between 1 and " + MAX + ": ");

        do {
            while (guess != answer) {
                numberOfGuesses++;
                guess = input.nextInt();

                if (guess == 101) {
                    break;
                } else if (guess > answer) {
                    System.out.println("Too High");
                    System.out.println("\nGuess again ");
                } else if (guess < answer) {
                    System.out.println("Too Low");
                    System.out.println("\nGuess again: ");
                } else {
                    System.out.println("Correct! The number was " + answer + ".");
                    System.out.println("It took you " + numberOfGuesses + " guesses.");
                }
            }

            System.out.println("\nWould you like to play again (yes/no)?");
            cont = input.nextLine();
        } while (cont.equals("yes");

        input.close();
    }
}