爲什麼在循環工作正常時不這樣做？

Question

我正在爲我的課程工作。該程序運行良好，直到它擊中我的最終程序，我一直在想它已經完成了2個小時左右。

這是它搞亂的代碼。

do { 
       System.out.println("Do you want to end program? (Enter n or y):"); 
       endProgram = Input.next(); 
       if(!endProgram.equals("y") || (!endProgram.equals("n"))){ 
        System.out.println("Do you want to end program? (Enter n or y):"); 
       } 
       if (endProgram.equalsIgnoreCase("n")){ 
        endProgram = "n"; 
        aui = true; 
       } 
       if (endProgram.equalsIgnoreCase("y")){ 
        endProgram = "y"; 
        aui = true; 
       } 
      } while(aui = false); 

我試圖搞亂其他如果然後切換到if。完整的代碼是

public static String endProgram = null; 
public static void main(String[] args) { 


    String MUR = "--------------Monthly Use Report--------------"; 
    int minutesAllowed; 
    int minutesUsed = 0; 
    int minutesOver; 
    double totalOwed; 
    double monthlyRate = 74.99; 
    double minOver = 0.20; 
    double realOwed; 
    boolean valid = false; 
    boolean over = false; 
    boolean aui = false; 

    Scanner Input = new Scanner(System.in); 

    System.out.println("Welcome to the Cell Phone Minutes Calculator."); 

    do { 

     do { 
      System.out.println("Please input the amount of minutes you were allowed to use per month."); 
      System.out.println("Please Enter a value between (200 - 800)"); 

      minutesAllowed = Input.nextInt(); 

     } while (minutesAllowed <= 199 || minutesAllowed >= 801);{ 

    } 

     do{ 
      try{ 
       System.out.println("How many minutes were used during the previous month?"); 
       minutesUsed = Input.nextInt(); 

       if(minutesUsed <= 1){ 
        System.out.println("--Invalid Input! Please use a positive number.--"); 
       } else { 
        valid = true; 
       } 
      } catch(Exception e){ 
       System.out.println("Invalid Input! Please try again."); 
       Input.next(); 
      } 
     }while(!valid); 

     minutesOver = minutesAllowed - minutesUsed; 

     if(minutesAllowed >= minutesUsed){ 
      System.out.println("You were not over your minutes for the month!"); 
     } else { 
      System.out.println("You were over your minutes by "+ Math.abs(minutesOver)); 
      over = true; 
     } 
      totalOwed = (Math.abs(minutesOver))*(minOver); 
      realOwed = totalOwed+monthlyRate; 
     System.out.println(MUR); 
     System.out.println("Minutes allowed were "+ minutesAllowed); 
     System.out.println("Minutes used were "+ minutesUsed); 
     if(over){ 
      System.out.println("Minutes over were "+ Math.abs(minutesOver)); 
      System.out.println("Total due is $"+ realOwed); 
     } else { 
      System.out.println("Total due is $"+ monthlyRate); 
     } 


    do { 
      System.out.println("Do you want to end program? (Enter n or y):"); 
      endProgram = Input.next(); 
      if(!endProgram.equals("y") || (!endProgram.equals("n"))){ 
       System.out.println("Do you want to end program? (Enter n or y):"); 
      } 
      if (endProgram.equalsIgnoreCase("n")){ 
       endProgram = "n"; 
       aui = true; 
      } 
      if (endProgram.equalsIgnoreCase("y")){ 
       endProgram = "y"; 
       aui = true; 
      } 
     } while(aui = false); 


    }while((endProgram.equalsIgnoreCase("n")) && (aui = false)); 

} 

}

很抱歉，如果代碼是馬虎不得。當我運行程序時，它會正常運行，除非我把兩個不正確的用戶輸入。例如，

程序運行//

--------------每月使用報告--------------

允許

分鐘，使用分別爲500

分鐘450

分鐘以上進行50

應付總額爲$ 84.99

你想結束程序嗎？ （輸入n或y）：

g

是否要結束程序？ （輸入n或y）：

如果我添加Input.Next（）;嵌套如果陳述到

if(!endProgram.equals("y") || (!endProgram.equals("n"))){ 
        System.out.println("Do you want to end program? (Enter n or y):"); 
        endProgram = Input.next(); 

它正確顯示它。我試圖搞亂整個項目中的大量循環。如果有人能幫助我，我將非常感激。對不起，如果這是困惑，我會迴應，如果你們有任何問題。預先感謝任何迴應，並對由此造成的不便深表歉意。

Answer 1

替換

while (aui = false); //here you are assigning aui to false value 

到

while (aui == false); //here you are comparing aui to false value 

=是作爲賦值運算符，==是比較運算符。

最好的做法是直接使用布爾，不是通過比較：

while (!aui);