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Query on implementation inheritance

Rajiv Rai
Ranch Hand

Joined: Jun 14, 2010
Posts: 57
I have been reading java interview questions and read the following about implementation inheritance.


"When using implementation inheritance, make sure that the sub-classes depend only
on the behavior of the superclass, not on the actual implementation."

Am confused about what the above statement means?
Winston Gutkowski
Bartender

Joined: Mar 17, 2011
Posts: 8626
    
  23

Rajiv Rai wrote:Am confused about what the above statement means?

Basically, what it means is that you shouldn't rely on a method having a particular implementation when you call it. And I'd go further and say that the statement applies whether you're using interface inheritance or not.

When tutorials refer to 'behaviour', they usually mean methods; when they talk about 'implementation', they're referring to code. You can call a method without having to know the code it contains.

Winston

Isn't it funny how there's always time and money enough to do it WRONG?
Articles by Winston can be found here
 
It is sorta covered in the JavaRanch Style Guide.
 
subject: Query on implementation inheritance