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About interface and abstract classes

Ja King
Greenhorn

Joined: May 15, 2009
Posts: 28
I know the definiton and how to use both interface and abstract....
but what is the use of both interface and abstract classes..
Maneesh Godbole
Saloon Keeper

Joined: Jul 26, 2007
Posts: 10535
    
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I find both your statements contradictory.
Would you care to rephrase your question?


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Frank Kellinghusen
Greenhorn

Joined: Jul 10, 2009
Posts: 11
vijai ganesh wrote:I know the definiton and how to use both interface and abstract....
but what is the use of both interface and abstract classes..


When you create an interface, you're defining a contract for what a class can do, without saying how the class will do it. It is up the the developer implementing the interface, how the class runs internally.

When you define an abstract class, you still defining a contract, but you can implement the class partially. When you know that some methods will be the same for all subtypes, you can provide those in your abstract class.

And finally, classes can implement many interfaces, but only can extend one class.

Harshit Rastogi
Ranch Hand

Joined: Apr 15, 2008
Posts: 131
Check out the question 4,5 & 6 . I hope this would help
Abstract class and interface


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