User Defined Exception

User-defined Exception:

• User-Defined Exception or custom exception is creating your own exception class.
• This can be done by extending the class Exception.

• Notes:
• 1. User-defined exceptions must extend Exception class.
• 2. The exception is thrown using the throw keyword.

• Example:

class JavaException{
   public static void main(String args[]){
  try{
       throw new MyException(2);
  }
 catch(MyException e){
    System.out.println(e) ;
 }
}
}
class MyException extends Exception{
   int a;
   MyException(int b) {
     a=b;
   }
   public String toString(){
     return ("Exception Number =  "+a) ;
  }
}

• Example:

Example:

class InvalidAgeException extends Exception{  

 InvalidAgeException(String s){  

  super(s);  

 }  

}  

class TestCustomException1{  

  

   static void validate(int age)throws InvalidAgeException{  

     if(age<18 b="" nbsp="">

      throw new InvalidAgeException("not valid");  

     else  

      System.out.println("welcome to vote");  

   }  

   public static void main(String args[]){  

      try{  

      validate(13);  

      }catch(Exception m){System.out.println("Exception occured: "+m);}  

  

      System.out.println("rest of the code...");  

  }  

}