Question

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

public class GuessingGame {

  public static void main (String [] args) {

    Random rand = new Random ();
    int numberToGuess = rand.nextInt (100);
    int numberOfTries = 0;
    Scanner input = new Scanner (System.in);
    int guess;

    boolean win = false;

    while (win == false); {

      System.out.println("Guess a number between 1 and 100:");
      guess = input.nextInt (); 
      numberOfTries++;

      if (guess == numberToGuess) {
        win = true;
      }

      else if (guess > numberToGuess) {
        System.out.println ("You guessed too low mate!");
      }

      else if (guess > numberToGuess) {
        System.out.println ("You guessed too high mate!") ;

        System.out.println("You win!!");
        System.out.println("The random number WAS!" + numberToGuess);
        System.out.println("It took you a wopping" + numberOfTries + "TRIES!");

      }
    }
  }
}

这是我的代码，当我尝试运行它时，它基本上卡在这里：

欢迎来到Java博士。工作目录是U：\ Downloads 运行GuessingGame

如何解决这个问题，我可以正确运行程序，而不会出现上述错误？

Answer 1

我看到两个错误。

while (win == false); {

应该是

while (win == false) {

（或while(!win) {）因为分号会创建一个空循环体。和

  else if (guess > numberToGuess) {
    System.out.println ("You guessed too low mate!");
  }

应该是

  else if (guess < numberToGuess) {
    System.out.println ("You guessed too low mate!");
  }

或者你有更高的两个测试（这种方式很有意义）。

Answer 2

详细说明艾略特的答案：

while (win == false); {
    // etc. etc. etc.
}

相当于

while (win == false)
     ;  // empty statement, does nothing
{
    // The body, which really isn't part of the while loop any more
}

与

具有相同的效果

while (win == false) { 
}

{
    // The part that isn't really part of the loop
}

由于win从false开始，所以在win以某种方式变为true之前，这将继续循环并且什么都不做，这当然永远不会发生。这就是程序陷入困境的原因 - 它处于无限循环中。

Answer 3

将while块修改为do-while块，如下所示

do{
      System.out.println("Guess a number between 1 and 100:");
      guess = input.nextInt (); 
      numberOfTries++;

      if (guess == numberToGuess) {
        win = true;
      }

      else if (guess < numberToGuess) {
        System.out.println ("You guessed too low mate!");
      }

      else if (guess > numberToGuess) {
        System.out.println ("You guessed too high mate!") ;

        System.out.println("You win!!");
        System.out.println("The random number WAS!" + numberToGuess);
        System.out.println("It took you a wopping" + numberOfTries + "TRIES!");

      }
    }while(win==false);

我点击“运行”它继续加载没有运行或停止的迹象

3 个答案: