异常处理

Question

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我希望它允许用户在输入错误后输入两个int。我尝试在catch块中继续，但它只抛出运行时错误。我只想让它在抛出错误后返回到main方法的顶部。看看图片中它是如何不允许用户输入任何数字的。我想修好那部分。

这是代码。这只是为了练习。

/**
practing exceptions, example 1 in book for exceptions 
*/ 

    import java.util.Scanner;

    public class PracticeExceptions extends Exception {

    public static void main(String[] args)
    {
     String response = "y";
     Scanner keyboard = new Scanner(System.in);

     do{ 
     int n1, n2;
     double r;
     System.out.println("Please enter two numbers");

     try{
            n1 = keyboard.nextInt();
            n2 = keyboard.nextInt();
            r = (double) n1/n2;     

        System.out.format("Your answer: %.2f %n", r);

       }catch(Exception a){

       System.out.println("Invaild input please try again");

       }

       System.out.println("Again (y/n)");
       response = keyboard.next();

       }while(response.equalsIgnoreCase("y"));
     }
   }

Answer 1

删除扫描仪缓冲区中的无效输入

 }catch(Exception a){
    System.out.println("Invalid input please try again");
    keyboard.next();
 }

代码现在将下拉到System.out.println("Again (y/n)");

如果您希望循环回到顶部，请在keyboard.next();之后添加一个continue