无效的用户输入，使用循环。

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英文:

invalid input from the user using loop

问题

  1. import java.util.Scanner;
  2. import java.util.Random;
  4. public class ShowWhatYouKnow {
  6.     public static void main(String[] args) {
  7.         Scanner key = new Scanner(System.in);
  8.         Random rd = new Random();
  9.         String ready;
  10.         int guess;
  12.         int[] dice = {1, 2, 3, 4, 5, 6};
  13.         
  14.         System.out.println("Welcome to the dice game!");
  15.         System.out.println();
  16.         System.out.println("Guess a number between 1-6 and win $50!!");
  17.         System.out.println("Are you ready?");
  18.         ready = key.nextLine();
  20.         // Implementing a loop to handle invalid input
  21.         while (!ready.equalsIgnoreCase("yes") && !ready.equalsIgnoreCase("no")) {
  22.             System.out.println("Invalid input!");
  23.             System.out.println();
  24.             System.out.println("Guess a number between 1-6 and win $50!!");
  25.             System.out.println("Are you ready?");
  26.             ready = key.nextLine();
  27.         }
  29.         if (ready.equalsIgnoreCase("yes")) {
  30.             System.out.println("Let The Game Begin!!");
  31.             System.out.println("-----------------------------------------");
  32.             // Rest of the code for the game
  33.         } else if(ready.equalsIgnoreCase("no")) {
  34.             System.out.println("You Exited The Program!! Bye!");
  35.             System.out.println("-----------------------------------------");
  36.             System.out.println();
  37.         }
  38.     }
  39. }
英文:

I am trying to make a while loop when the input from the user is invalid meaning it is not "yes" or "no" so that the question would appear again. i would appreciate it if you could help me out here!!! thanks(i have deleted most of the code except for the problem because it was too long !!)
code:

  1. import java.util.Scanner;
  2. import java.util.Random;
  3. public class ShowWhatYouKnow {
  4. public static void main(String[] args) {
  5. Scanner key = new Scanner(System.in);
  6. Random rd = new Random();
  7. String ready;
  8. int guess;
  9. int[] dice = {1, 2, 3, 4, 5, 6};
  10. System.out.println("Welcome to dice game!");
  11. System.out.println("");
  12. System.out.println("Guess a number between 1-6 and win $50!!");
  13. System.out.println("Are you ready??");
  14. ready = key.nextLine();
  15. // trying to do a do while here so if the user inputs the invalid option this would accur again and again
  16. /*
  17. System.out.println("invalid input !");
  18. System.out.println("");
  19. System.out.println("Guess a number between 1-6 and win $50!!");
  20. System.out.println("Are you ready??");
  21. ready = key.nextLine();
  22. */
  23. if (ready.equalsIgnoreCase("yes")) {
  24. System.out.println("Let The Game Begin!!");
  25. System.out.println("-----------------------------------------");
  26. }
  27. } else if(ready.equalsIgnoreCase("no")){
  28. System.out.println("You Exited The Program!! Bye!");
  29. System.out.println("-----------------------------------------");
  30. System.out.println("");
  31. }
  32. }
  33. }

答案1

得分: 0

使用一个无限循环，并在输入正确时中断它

  1.     while (true) {
  2.         System.out.println("猜一个1-6之间的数字，赢取$50奖金！！");
  3.         System.out.println("你准备好了吗？");
  4.         ready = key.nextLine();
  5.         if (ready.equalsIgnoreCase("是")) {
  6.             System.out.println("游戏开始！");
  7.             System.out.println("-----------------------------------------");
  8.             break;
  9.         } else if (ready.equalsIgnoreCase("否")) {
  10.             System.out.println("你退出了程序！再见！");
  11.             System.out.println("-----------------------------------------");
  12.             System.out.println("");
  13.             break;
  14.         } else {
  15.             System.out.println("无效的输入！");
  16.         }
  17.     }
英文:

Use an infinite loop and break it when the input is correct

  1.     while (true) {
  2. System.out.println("Guess a number between 1-6 and win $50!!");
  3. System.out.println("Are you ready??");
  4. ready = key.nextLine();
  5. if (ready.equalsIgnoreCase("yes")) {
  6. System.out.println("Let The Game Begin!!");
  7. System.out.println("-----------------------------------------");
  8. break;
  9. } else if (ready.equalsIgnoreCase("no")) {
  10. System.out.println("You Exited The Program!! Bye!");
  11. System.out.println("-----------------------------------------");
  12. System.out.println("");
  13. break;
  14. } else {
  15. System.out.println("invalid input !");
  16. }
  17. }

答案2

得分: 0

你可以使用 [Do-while 循环][1] 来解决你的问题：如果用户输入不是 "yes" 或 "no"，问题将会再次出现。你可以像这样编写主方法：

  1. public static void main(String[] args) {
  2.     Scanner key = new Scanner(System.in);
  3.     Random rd = new Random();
  4.     String ready;
  5.     int guess;
  7.     int[] dice = {1, 2, 3, 4, 5, 6};
  9.     System.out.println("欢迎来到骰子游戏！");
  10.     do {
  11.         System.out.println("");
  12.         System.out.println("猜一个从1到6的数字，赢取 $50！！");
  13.         System.out.println("你准备好了吗？");
  14.         ready = key.nextLine();
  15.     } while (!ready.equalsIgnoreCase("yes") && !ready.equalsIgnoreCase("no"));
  16.     if (ready.equalsIgnoreCase("yes")) {
  17.         System.out.println("让游戏开始吧！");
  18.         System.out.println("-----------------------------------------");
  20.     } else if (ready.equalsIgnoreCase("no")) {
  21.         System.out.println("你退出了程序！再见！");
  22.         System.out.println("-----------------------------------------");
  23.         System.out.println("");
  24.     }
  25. }
  27.   [1]: https://docs.oracle.com/javase/tutorial/java/nutsandbolts/while.html
  30. <details>
  31. <summary>英文:</summary>
  33. You could use [Do-while loop][1] to solve your problem: the question will appear again if the input from user is not &quot;yes&quot; or &quot;no&quot;. You could write the main method like this:
  35.     public static void main(String[] args) {
  36.         Scanner key = new Scanner(System.in);
  37.         Random rd = new Random();
  38.         String ready;
  39.         int guess;
  41.         int[] dice = {1, 2, 3, 4, 5, 6};
  43.         System.out.println(&quot;Welcome to dice game!&quot;);
  44.         do {
  45.             System.out.println(&quot;&quot;);
  46.             System.out.println(&quot;Guess a number between 1-6 and win $50!!&quot;);
  47.             System.out.println(&quot;Are you ready??&quot;);
  48.             ready = key.nextLine();
  49.         } while (!ready.equalsIgnoreCase(&quot;yes&quot;) &amp;&amp; !ready.equalsIgnoreCase(&quot;no&quot;));
  50.         if (ready.equalsIgnoreCase(&quot;yes&quot;)) {
  51.             System.out.println(&quot;Let The Game Begin!!&quot;);
  52.             System.out.println(&quot;-----------------------------------------&quot;);
  54.         } else if (ready.equalsIgnoreCase(&quot;no&quot;)) {
  55.             System.out.println(&quot;You Exited The Program!! Bye!&quot;);
  56.             System.out.println(&quot;-----------------------------------------&quot;);
  57.             System.out.println(&quot;&quot;);
  58.         }
  59.     }
  62.   [1]: https://docs.oracle.com/javase/tutorial/java/nutsandbolts/while.html
  64. </details>

huangapple
  • 本文由 发表于 2020年8月18日 10:05:28
  • 转载请务必保留本文链接：https://go.coder-hub.com/63460884.html
  • arrays
  • java
  • javascript
  • loops
  • while-loop
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