如何使用用户输入启动和结束循环？

Question

我无法确定如何提示允许用户输入数字或字符来启动或结束循环的问题。

以下是代码

import java.util.Scanner; 

public class diceRoller{ 
    public static void main(String[] args){  

     Scanner keyboard = new Scanner(System.in); 

     int score; 
     int sum=0; 
     int roll1 = genRanInRange(1, 6); 
     int roll2 = genRanInRange(1, 6); 
     int roll3 = genRanInRange(1, 6); 
     System.out.println("Your rolls were: " + " " + roll1 + " " + roll2 + " " + roll3);  
      if (roll1 == roll2 || roll2 == roll3 || roll1 == roll3){ // start of first loop 

       System.out.println("You had 2 matching rolls! You gain 50 points."); 
       score = 50; 
       sum += score; 
       if (roll1 == roll2 && roll2 == roll3 && roll1 == roll3){ // nested loop 

       int rollSum = roll1 + roll2 + roll3; 
        if (rollSum == 18){ // nested loop 2 

        System.out.println("You had 3 matching 6's! You gain 500 points."); 
        score = 500;       
        sum += score; 
        } // end nested loop 2 

       } // end nested loop 

      } // end of first loop 

      else { 
       System.out.println("Sorry, you had 0 matching die."); 
       score = 1; 
       sum -= score; 
      } 
       System.out.println("Your score was: " + sum); 

      if (sum > 0){ 
       System.out.println("Would you like to continue?"); 
       } 

      else{ 

       System.out.println("You are out of points. Would you like to restart?"); 
       } 

    } // end Main 

    public static int genRanInRange(int start, int end) 
    { 
     return (int)(Math.random()*(end-start+1.0)) + start; 
    } // end genRanInRange 

} // end Dice Roller 

Answer 1

这应该做的伎俩

System.out.print("Would you like to continue? Y/N: "); 
String UserResp = scanner.nextLine(); 

把代码的其余部分在一个while循环。 并且在开头定义的布尔值对于第一个循环为true，然后将UserResp与Y或N进行比较以设置布尔值。

Answer 2

这里是将工作的代码：

import java.util.Scanner; 

public class DiceRoller{ 
    public static void main(String[] args){  

     Scanner keyboard = new Scanner(System.in); 

     int score; 
     int sum=0; 
     char ans='y'; 
     while(ans=='Y'||ans=='y'){ //loop while user says Y 
      int roll1 = genRanInRange(1, 6); 
      int roll2 = genRanInRange(1, 6); 
      int roll3 = genRanInRange(1, 6); 
      System.out.println("Your rolls were: " + " " + roll1 + " " + roll2 + " " + roll3);  
      if (roll1 == roll2 || roll2 == roll3 || roll1 == roll3){ // start of first loop 
       System.out.println("You had 2 matching rolls! You gain 50 points."); 
       score = 50; 
       sum += score; 
       if (roll1 == roll2 && roll2 == roll3 && roll1 == roll3){ // nested loop 
       int rollSum = roll1 + roll2 + roll3; 
        if (rollSum == 18){ // nested loop 2 

        System.out.println("You had 3 matching 6's! You gain 500 points."); 
        score = 500;       
        sum += score; 
        } // end nested loop 2 

       } // end nested loop 

      } // end of first loop 

      else { 
       System.out.println("Sorry, you had 0 matching die."); 
       score = 1; 
       sum -= score; 
      } 
       System.out.println("Your score was: " + sum); 

      if (sum > 0){ 
       System.out.println("Would you like to continue?(Y/N) "); 
        ans=keyboard.next().charAt(0); 
       } 
      else{ 
       System.out.println("You are out of points. Would you like to restart?(Y/N) "); 
       ans=keyboard.next().charAt(0); 
      } 

     } 
     keyboard.close(); //Don't forget to close sccaner. 
    } // end Main 

    public static int genRanInRange(int start, int end) 
    { 
     return (int)(Math.random()*(end-start+1.0)) + start; 
    } // end genRanInRange 

} // end Dice Roller 

我改变你的类的市值从diceRoller到DiceRoller。

类名应该总是有它的第一个字母用大写'

一两件事：

不要忘记关闭扫描仪。