public static void main(String[] args) {
    System.out.println("Welcome to Guessing Game");
    guessNumber();
    System.out.println("Guessing game terminate, thank you");
}

private static void guessNumber() {
    Scanner uInput = new Scanner(System.in);
    Random randNum = new Random();
    int guessNumber, number, count = 0;
    String in;
    char again;
    boolean isCorrect = false;

    number = randNum.nextInt(50); // random number in the range of 1..50

    while (!isCorrect) {
        System.out.println("Enter a number to guess: ");
        guessNumber = uInput.nextInt(); // get guess number from user

        count += 1;

        if (guessNumber > number) {
            System.out.println("Too big");
        } else if (guessNumber < number) {
            System.out.println("Too small");
        } else {
            System.out.println("Success");
            isCorrect = true;
        }
    }

    System.out.println("You successfully guess the number in " + count + " attempts");
    System.out.println("Do you want to play again? yes/no");
    in = uInput.next();

    again = in.charAt(0); //again will hold the first character from in var
    if (again == 'Y' || again == 'y') {
        guessNumber();
    }
}

您所要做的就是用while循环替换do while循环。但关键是，您必须将初始值“y”设置为您的字符以启动while循环。循环的条件将是相同的。代码如下：char again='y'；

while (again == 'Y' || again == 'y') {
        System.out.println("Welcome to Guessing Game");
        number = randNum.nextInt(50);

        for (int i = 0; i < 5; i++) {
            System.out.println("Enter a number to guess: ");
            guessNumber = uInput.nextInt();

            if (guessNumber > number) {
                System.out.println("Too big");
            } else if (guessNumber < number) {
                System.out.println("Too small");
            } else {
                System.out.println("Success");
                count += 1;
                break;
            }
        }

        System.out.println("You have successfully guessed the number for " + count + " times");
        System.out.println("Do you want to play again? ");
        in = uInput.next();

        again = in.charAt(0); //again will hold the first character from in var
    }

    System.out.println("Guessing game terminate, thank you");

我必须注意到你的 count 变量，包含用户成功猜到的游戏数，而不是单个游戏中的尝试次数。如果你想处理这个问题，创建 attempts while循环中的变量，并在用户尝试时增加它。我也换了线 in = uInput.nextLine(); 至 in = uInput.next(); 因为我相信你的扫描仪输入会被跳过。