Question

Java OOP Extending Classes and Inheritance

Asked by: ksfok

Given an abstract ItemBase class, two subclasses A and B are extended from it with methods specific to each one.  For example:

ItemBase has generic method V, W
subclass A has specfic method X
subclass B has specfic method Y

How can the above design be implemented so that ItemBase be used as an Array that contains objects of A or B calling their individual method X or Y? Can methods X and Y be omitted in Itembase or should they be defined in it? How?
Thanks for any help.

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Asked On
2009-04-23 at 17:52:59ID24351094
Topic

New to Java Programming

Participating Experts
1
Points
500
Comments
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Answers

 

by: VenabiliPosted on 2009-04-24 at 06:13:12ID: 24224666

If you need to call them and they are not in ItemBase, you will need to cast the objects...
What I would do would be:
Make a method someMethod in ItemBase and make it abstract
Then implement it in A and B instead of implementing differently named methods. And make this implementation call the individual X and Y methods
Then when you invoke the someMethod to an ItemBase object, it will fall to the proper method based on what the real type is.

That's the cleanest way I can think of.

 

by: ksfokPosted on 2009-04-24 at 15:12:46ID: 24229753

  1. Make a method someMethod in ItemBase and make it abstract 
  2. Then implement it in A and B instead of implementing differently named methods. And make this implementation call the individual X and Y methods  
    3. </OL>

    Please kindly provide code syntax for the above.

    Thanks much.

20120131-EE-VQP-002

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