Difference between Abstract Class and Interface, Which scenarios we are using both?

[Koti Samadhi]

Difference between Abstract Class and Interface, Which scenarios we are using both?

Any one can , Please reply with examples.

Thanks
Koti

[Anu satya]

Abstract class can also have non-abstract methods in it. but, interfaces can't have non-abstract methods.

Abstract class can have constructors where as interfaces can't have constructors

Abstract class can be extended to only one sub class....(Single inheritance) where as you can implement multiple interfaces

bot abstract classes and interfaces can't be instantiated.

Regards,
Anu

[Vijitha Kumara]

Koti Samadhi wrote:Difference between Abstract Class and Interface, Which scenarios we are using both?

Hi Koti,
Both expose the concept "Abstraction". Abstract classes are useful when you need to provide a common set of method implementation(s) for all the subclasses to share. Most modern frameworks build around the concept of interfaces.

[Santhosh Reddy]

Purpose of both abstract class and interface is almost the same, except you can use abstract class when some of the implementation is fixed(few methods are implemented) and rest of the implemtation is left to the user.

[Campbell Ritchie]

Santhosh Reddy wrote: . . . and rest of the implemtation is left to the user.

Probably better to say "and the rest of the implementation will be different in the subclasses."

[s.palanivel rajan]

hi this is simple....
In Interface only abstract and public access specifiers are allowed...
In abstract classes all normal access specifiers are allowed..
abstract classes should not be instantiated..
Use abstract keyword for abstract classes..
Use interface keyword for interfaces..

[Rahul P Kumar]

s.palanivel rajan wrote:hi this is simple....
abstract classes should not be instantiated..
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Do you mean that if you want you can but you should not ?

s.palanivel rajan wrote:

cool yaar. from where you have picked up these habits ?

[s.palanivel rajan]

why ??dont you saw the left side of message window

[Campbell Ritchie]

Please avoid pretty coloured text; many people find it difficult to read. I have changed the previous text to black.

[s.palanivel rajan]

ok cambell.. no problem i understand...
but if it is the case then why these colours are given...

[Rakib Jahin]

nice replies.it was helpful for me

[Campbell Ritchie]

Thank you. A few colours might be helpful, but . . .