Abstract class vs. interface

[Inam ur Rehman]

hello Guys I have a nice topic to discuss about, which always asked in every interview which is that...............
what is the difference between abstract class and interface, if we do same thing with abstract class as well as with interface then what is the difference?

[JosAH]

hello Guys I have a nice topic to discuss about, which always asked in every interview which is that...............
what is the difference between abstract class and interface, if we do same thing with abstract class as well as with interface then what is the difference?

This topic has been discussed to death many many times. Google knows all
about it as well.

kind regards,

Jos

[cygsoft]

In abstract class there can be a non-abstract method with implementation could be present. Whereas in interface no method should be implemented.

[Inam ur Rehman]

This topic has been discussed to death many many times. Google knows all
about it as well.

kind regards,

Jos

Yes google knows about it but i cant find any simple example which clarify the difference to person like me(who is not very claver in programming).
kindly give me any simple example which shows such a functionality, which is only possible by abstract class and not possible by interface or vise-versa.

thanks.
Inam ur Rehman.

[JosAH]

Yes google knows about it but i cant find any simple example which clarify the difference to person like me(who is not very claver in programming).
kindly give me any simple example which shows such a functionality, which is only possible by abstract class and not possible by interface or vise-versa.

thanks.
Inam ur Rehman.

You have to start thinking in types; everything is a type. An instance of a type
can do things, possbily given instances of (other) types. A interface is a type
and an (abstract) class is a type plus an implementation of the things it can do.

If a class implements everything an interface said it can do, the class is a
concrete class; otherwise it must be abstract. Interfaces (which are pure types)
are also called 'contracts'. For a class, in order to obey that contract it must
implement everything the interface 'promises' that it can do.

If/when you start coding, remember this 'mantra':

Code to the interface (type), not the implementation (class).

kind regards,

Jos