Question

CREATE A NEW Java PROGRAM that demonstrates :

1.1 numeric and 1 string exception

2. Create your own user defined exception, COMMENT it well, and add code so that it is thrown.

Answer 1

Java Program:

//Exception Class
class UserException extends Exception{
   String str1;
   // Constructor
   UserException(String val) {
       //Storing message
       str1=val;
   }
   //Method that prints the message
   public String toString(){
       return ("UserException Occurred: " + str1) ;
   }
}

class ExceptionDemonstrater {
   //Main method
   public static void main(String[] args) {
      
       //Number Exception
       try
       {
           //Trying to convert String to integer - Generates Exception
           int n = Integer.parseInt("One");
       }
       catch(NumberFormatException ex)
       {
           //Handling and printing exception message
           System.out.println(ex.toString());
       }
      
       //String Exception
       try
       {
           //Sample String
           String s = "Hello World";
           //Trying to fetch a character from string with invalid index value - Generates Exception
           char ch = s.charAt(100);
       }
       catch(StringIndexOutOfBoundsException ex)
       {
           //Handling and printing exception message
           System.out.println(ex.toString());
       }
      
       //User Defined Exceptions
       try
       {
           //Throwing Exception
           throw new UserException("User Defined Exception Generated.");
       }
       catch(UserException ex)
       {
           //Handling and printing exception message
           System.out.println(ex.toString());
       }
   }
}

_________________________________________________________________________________________

Sample Run: