虽然循环不工作在Java

Question

我想要得到这个一遍又一遍地问问题，而用户输入一个'Y'。并停止并返回Event.displayFinalResults();当用户输入一个'N'

我现在正在一个连续的循环。我错过了一些东西或者我的布局错了。任何帮助都会很棒。

  System.out.println("Is there anymore amounts you want to add?(Y/N): "); 
      Scanner keyboard = new Scanner(System.in); 
      char choice = keyboard.next().charAt(0); 
      choice = Character.toUpperCase(choice); 
      if(choice == 'Y') 
      { 
       do 
       { 
        System.out.println("Is there anymore amounts you want to add?(Y/N): "); 
        choice = keyboard.next().charAt(0); 
        choice = Character.toUpperCase(choice); 

        readValidateAmountType(); 
        readValidateAmount(); 
       } 
       while(choice =='Y'); 

      } 
      else 
      { 
       Event.displayFinalResults(); 
      } 

再次感谢。

Answer 1

您的程序询问是/否问题，那么如果您回答是，它会在询问金额值之前再次询问相同的问题开始循环。

您可能需要在之前询问金额值，然后再次询问是/否问题。

如果用户回答否，循环将退出（请求多​​一个金额值后），但Event.displayFinalResults()将不会执行。删除else子句，因此Event.displayFinalResults()是否输入if声明与否。

System.out.println("Is there anymore amounts you want to add?(Y/N): "); 
Scanner keyboard = new Scanner(System.in); 
char choice = keyboard.next().charAt(0); 
choice = Character.toUpperCase(choice); 
if (choice == 'Y') 
{ 
    do 
    { 
     readValidateAmountType(); 
     readValidateAmount(); 

     System.out.println("Is there anymore amounts you want to add?(Y/N): "); 
     choice = keyboard.next().charAt(0); 
     choice = Character.toUpperCase(choice); 
    } 
    while(choice =='Y'); 
} 
Event.displayFinalResults(); 

Answer 2

我发现的一个问题是，您的while循环位于if语句中。一旦你退出while循环，它不会运行else块内的代码，因为if条件已经成立。

因此，请尝试删除else块。这将确保while循环退出时调用Event.displayFinalResults方法。

 System.out.println("Is there anymore amounts you want to add?(Y/N): "); 
     Scanner keyboard = new Scanner(System.in); 
     char choice = keyboard.next().charAt(0); 
     choice = Character.toUpperCase(choice); 

if(choice == 'Y') 
     { 
      do 
      { 
       System.out.println("Is there anymore amounts you want to add?(Y/N): "); 
       choice = keyboard.next().charAt(0); 
       choice = Character.toUpperCase(choice); 

       readValidateAmountType(); 
       readValidateAmount(); 
      } 
      while(choice =='Y'); 

     } 

     Event.displayFinalResults(); 

Answer 3

如下你可以做到这一点使用break;：

do { 
    System.out.println("Is there anymore amounts you want to add?(Y/N): "); 
    choice = keyboard.next().charAt(0); 
    choice = Character.toUpperCase(choice); 
    if (choice !='Y') { 
     break; 
    } 

    readValidateAmountType(); 
    readValidateAmount(); 
} while(true); 

Event.displayFinalResults(); 

Answer 4

尝试以下操作进行：

public void answering(char answer){ 
     if(answer == 'Y' || answer == 'y'){ 
      System.out.println("Answering"); 
     } else if(answer == 'N' || answer == 'n'){ 
      System.out.println("Not answering"); 
    } 

而是循环的，调用此方法时，你要问...

Answer 5

清除代码和紧凑：

Scanner keyboard = new Scanner(System.in); 
char choice; 
do { 
    System.out.println("Is there anymore amounts you want to add?(Y/N): "); 
    choice = keyboard.next().charAt(0); 
    choice = Character.toUpperCase(choice); 
    if(choice == 'Y') { 
     readValidateAmountType(); 
     readValidateAmount(); 
    } 
} while(choice == 'Y');  
Event.displayFinalResults();