异常类try-catch(课本)

编写过程中的错误：

1： MyException()掉括号

2：Exception 拼写错误

3：if(n>0)写成int

 

 

import java.util.*;
import java.io.*;
import java.awt.*;
class MyException extends Exception
{
 String message;
 MyException()
  {message="数字不是正数";}
 public String toString()
  {return message;} 
}

class YourException extends Exception
{
 String message;
 YourException()
  {message="数字不是偶数";}

 public String toString()
  {return message;}
}

class A
{
 public void f(int n) throws MyException ,YourException
  {
   if(n<0)
   {throw new MyException();}
   if(n%2!=0)
   {throw new YourException();}
   double number=Math.sqrt(n);
   System.out.println(number);
  }
}

public class Example
{
 public static void main(String args[])
  {
  A a=new A();
  try
   {a.f(9);}
  catch(MyException e)
   {System.out.println(e.toString());}
  catch(YourException e)
   {System.out.println(e.toString());}
  }
}