aspose file tools*
The moose likes Beginning Java and the fly likes whether the eg overrides or overloads Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Java » Beginning Java
Bookmark "whether the eg overrides or overloads" Watch "whether the eg overrides or overloads" New topic
Author

whether the eg overrides or overloads

Praveen palukuri
Ranch Hand

Joined: Feb 10, 2005
Posts: 65
hi,
i've some doubt regarding the following eg

class A
{
protected metha()
{...}
}
class B extends A
{
private metha()
{....}
}

whether method in class B overrides/overloads method in class A.

Thank you in advance.
Alana Sparx
Ranch Hand

Joined: Feb 14, 2006
Posts: 121
Sorry mate, it does neither - it'll throw an exception.
Praveen palukuri
Ranch Hand

Joined: Feb 10, 2005
Posts: 65
may i know the reason to cause exception.
Shyam Prasad Murarka
Ranch Hand

Joined: May 02, 2005
Posts: 209
Dear Praveen,
Over-riding: This is done when you provide a different implementation of a method (belonging to a super-class) in your class. This over-riding method should have the same signature as your superclass method. And along with that the access modifier that you specify for the over-riding method should have a scope equal to OR higher than the superclass method.
Hope I am not confusing matters here.
As you can see from the example you provided, the method in your subclass had a scope smaller than the superclass, so the compiler throws an error.
Over-loading: This is done when the method signature is the same but either of the following conditions should be met:
  • the number of parameters is different
  • the order of the parameters are different
  • the type of parameters are different


  • I have a feeling I have written a lot of information that may be incorrect. So just wait until an expert comes in and verifies the information. I just wrote my understanding of Overloading/Over-riding methods.
    [ April 20, 2006: Message edited by: Shyam Murarka ]

    With Best Regards,
    Shyam Prasad Murarka
    Rodrigo Alvarez
    Ranch Hand

    Joined: Apr 10, 2006
    Posts: 75
    Hi praveen,

    your metha() in class B is (trying to) override the metha() in class A. Overloading is when you declare a method with the same name but a different signature (e.g.metha(int a) ).

    Anyway, in yuor example it would not work : you cannot reduce the visibility of a method when you override it (and private is a "smaller" visibility than "protected").

    => you would get a compile time error

    Cheers


    It is a mistake to think you can solve any major problems just with potatoes.<br />--Douglas Adams
    Vishnu Prakash
    Ranch Hand

    Joined: Nov 15, 2004
    Posts: 1026

    Sorry mate, it does neither - it'll throw an exception.


    WRONG.

    It will NOT throw a runtime exception.

    You will get compile time error stating weaker access privilege


    Servlet Spec 2.4/ Jsp Spec 2.0/ JSTL Spec 1.1 - JSTL Tag Documentation
    Ernest Friedman-Hill
    author and iconoclast
    Marshal

    Joined: Jul 08, 2003
    Posts: 24183
        
      34

    Unfortunately, this mistake is an all too common one: referring to compile errors as "exceptions."


    [Jess in Action][AskingGoodQuestions]
    Alana Sparx
    Ranch Hand

    Joined: Feb 14, 2006
    Posts: 121
    I consider my slack, slapdash and lackadaisical attitude to semantics duly chastised and promise to sharpen up my attitude forthwith.

    Basically dude, it isnae gonnae wurk.
     
    I agree. Here's the link: http://aspose.com/file-tools
     
    subject: whether the eg overrides or overloads