keywords implements and extends

[vikas motkur]

How are the key words different both are used to incorporate inheritance..why is there a difference???

[David McCombs]

To put it simply extends is used to inherit other classes both abstract and non-abstract. implements is used in classes to inherit interfaces.

[Remko Strating]

implements is used in classes to inherit interfaces

You mean you will provide a legal implementation of the interface so that code outside your class can be sure that certain implementation of methods exist.

[David McCombs]

Originally posted by Remko Strating:


You mean you will provide a legal implementation of the interface so that code outside your class can be sure that certain implementation of methods exist.

Yeah, I didn't like that when I wrote it, but couldn't think of a better answer at the time. Not all interfaces have methods defined, so perhaps a better explanation is when a class needs to use the implied contract of an interface.

And if an interface "inherits" another interface, extends is used.

[ August 08, 2007: Message edited by: David McCombs ]
[ August 08, 2007: Message edited by: David McCombs ]