如果用戶輸入Y，如何保持程序運行？

Question

這裏是我的代碼：

import java.util.*; 

class Main { 

    public static void main(String[] args) { 
     Scanner Keyboard = new Scanner(System.in); 
     { 
      System.out.println("What is the answer to the following problem?"); 

      Generator randomNum = new Generator(); 
      int first = randomNum.num1(); 
      int second = randomNum.num2(); 
      int result = first + second; 
      System.out.println(first + " + " + second + " ="); 

      int total = Keyboard.nextInt(); 

      if (result != total) { 
       System.out.println("Sorry, wrong answer. The correct answer is " + result); 
       System.out.print("DO you to continue y/n: "); 
      } else { 
       System.out.println("That is correct!"); 

       System.out.print("DO you to continue y/n: "); 

      } 

     } 
    } 

} 

我試圖讓程序繼續運行，但如果用戶輸入y和如果他進入ñ關閉。

我知道我應該使用while循環，但不知道應該在哪裏開始循環。

Answer 1

您可以使用一個循環，例如：

Scanner scan = new Scanner(System.in); 
String condition; 
do { 
    //...Your code 
    condition = scan.nextLine(); 

} while (condition.equalsIgnoreCase("Y")); 

Answer 2

這是一個很好的嘗試。只需添加一個簡單的while循環，並促進用戶輸入您詢問後，如果他們想繼續與否：

import java.util.*; 

class Main 
{ 
    public static void main(String [] args) 
    { 
     //The boolean variable will store if program needs to continue. 
     boolean cont = true; 

     Scanner Keyboard = new Scanner(System.in); 

     // The while loop will keep the program running unless the boolean 
     // variable is changed to false. 
     while (cont) { 

      //Code 

      if (result != total) { 

       System.out.println("Sorry, wrong answer. The correct answer is " + result); 

       System.out.print("DO you to continue y/n: "); 

       // This gets the user input after the question posed above. 
       String choice = Keyboard.next(); 

       // This sets the boolean variable to false so that program 
       // ends 
       if(choice.equalsIgnoreCase("n")){ 
        cont = false; 
       } 

      } else { 

       System.out.println("That is correct!"); 

       System.out.print("DO you to continue y/n: "); 

       // This gets the user input after the question posed above. 
       String choice = Keyboard.next(); 

       // This sets the boolean variable to false so that program 
       // ends 
       if(choice.equalsIgnoreCase("n")){ 
        cont = false; 
       } 
      } 
     } 
    } 
} 

您也可以在其他類型的讀取多達循環，並嘗試以其他方式實施此代碼：Control Flow Statements。