循环输出

Question

程序将为第一个数字猜测生成正确的输出，但在用户输入第二个猜测后，根本没有输出。请帮忙！致谢

    final int number = (int)((Math.random()*99)+1);
    int counter = 0;
    System.out.print("Enter a guess between 1 and 100: ");
    while (keyboard.nextInt() > number) {
        System.out.println("Your guess was too high. Try again.");
        counter++;
        System.out.print("Enter a guess between 1 and 100: ");
    }
    while (keyboard.nextInt() < number) {
        System.out.println("Your guess was too low. Try again.");
        counter++;
        System.out.print("Enter a guess between 1 and 100: ");
    }
    while (keyboard.nextInt() == number) {
        System.out.println("Congratulations! Your guess was correct!");
        counter++;
        System.out.println("I had chosen " + number + " as the target number.");
        System.out.println("You guessed it in " + counter + " tries.");
        if (counter == 1) {
            System.out.println("That was lucky!");
        }
        if (counter >= 2 || counter <= 4) {
            System.out.println("That was amazing!");
        }
        if (counter == 5 || counter == 6) {
            System.out.println("That was good.");
        }
        if (counter == 7) {
            System.out.println("That was OK.");
        }
        if (counter == 8 || counter == 9) {
            System.out.println("That was not very good.");
        }
        if (counter >= 10) {
            System.out.println("This just isn't your game.");
        }

Answer 1

你真的需要改变你的设计模式。

一旦你不能满足其中一个循环中的条件，你的代码将永远不会回来。

你应该只有1 while个循环用于猜测阶段。你的代码应该是这样的

while(someCondition)
{  
    int num = keyboard.nextInt()
    if (num  > number) {   
        ...      
    }
    else if (num  < number) {  
        ...
    }
    else if (num  == number) {
        ...
    }
}

Answer 2

• 您的while循环应为if语句。
• 应该有while循环（实际上）所有代码

您的代码应大致如下：

while(true) {
    // prompt for input
    // read input
    // break from loop if input is the exit input, eg -1
    // check input - essentially change your whiles to ifs
}

Answer 3

此块似乎无法正常工作：

while (keyboard.nextInt() > number) {
    System.out.println("Your guess was too high. Try again.");
    counter++;
    System.out.print("Enter a guess between 1 and 100: ");
}
while (keyboard.nextInt() < number) {
    System.out.println("Your guess was too low. Try again.");
    counter++;
    System.out.print("Enter a guess between 1 and 100: ");
}

假设用户输入-1然后输入101.您将进入下一个循环。因此，您可能希望将其更改为：

boolean retry = true;
while ( retry ) {
    counter++;
    int n = keyboard.nextInt();
    if( n > number ) {
      System.out.println("Your guess was too high. Try again.");
    }
    else if( n < number ) {
      System.out.println("Your guess was too low. Try again.");
    }
    else {
      //number found
      retry = false;
    }

    if( retry ) {
        System.out.prnt("Enter a guess between 1 and 100: ");
    } 
}

Answer 4

使用while语句时存在一些问题。

您可以在此处找到正确的代码版本：

public static void main(final String[] args) {
    final Scanner keyboard = new Scanner(System.in);
    final int number = (int) ((Math.random() * 99) + 1);
    int counter = 0;
    System.out.print("Enter a guess between 1 and 100: ");
    int user_number;
    do {
        user_number = keyboard.nextInt();
        if (user_number > number) {
            System.out.println("Your guess was too high. Try again.");
            System.out.print("Enter a guess between 1 and 100: ");
            counter++;
        } else if (user_number < number) {
            System.out.println("Your guess was too low. Try again.");
            System.out.print("Enter a guess between 1 and 100: ");
            counter++;
        }
    } while (user_number != number);
    System.out.println("Congratulations! Your guess was correct!");
    counter++;
    System.out.println("I had chosen " + number + " as the target number.");
    System.out.println("You guessed it in " + counter + " tries.");
    if (counter == 1) {
        System.out.println("That was lucky!");
    }
    if ((counter >= 2) || (counter <= 4)) {
        System.out.println("That was amazing!");
    }
    if ((counter == 5) || (counter == 6)) {
        System.out.println("That was good.");
    }
    if (counter == 7) {
        System.out.println("That was OK.");
    }
    if ((counter == 8) || (counter == 9)) {
        System.out.println("That was not very good.");
    }
    if (counter >= 10) {
        System.out.println("This just isn't your game.");
    }
}

Answer 5

while(someCondition)
{

    if (keyboard.nextInt() > number) {

        ...

    } else if(keyboard.nextInt() < number) {

        ...

    } else {

        ...

    }

}