Difference between abstract & interface? [Resolved]

abstract classes are generic classes. abstract classes are used to create as reference to object
like
myAbstractClass objclass = new myClass();

abstract can have one or more concrete methods and abstract methods.
abstract classes cannot be instantiated.

An interface has no implementation; it only has the signature.all the methods in interface should be implemented in derived class
we can implement more than one interface in class.but cannot be done in abstract class

Rajendra.prasad, if this helps please login to Mark As Answer. | Alert Moderator

Please go through below link, you will learn a lot about Abstract class and interface.

http://www.dotnetfunda.com/interview/exam332-when-to-use-interface-over-abstract-class-.aspx
http://www.dotnetfunda.com/interview/exam90-what-is-abstract-class.aspx
http://www.dotnetfunda.com/articles/article467-abstract-class--explained.aspx

Thank you.

Regards,
Raja, USA

Rajendra.prasad, if this helps please login to Mark As Answer. | Alert Moderator

Abstract Class Interface

1) Abstract Class can have one more 1) Only signature of methods. No implementation
Abstract methods and Non-Abstract methods inside of the interface
2) It can support all type of Access modifier 2) Public only support for interface.
(ie: Public,Private .. etc)
3) Abstract can have constructor or destructor 3) Don't have any Constructor or Destructor
4) It don't support multiple inheritance 4) It support multiple interface.

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