Extending means adding new method definitions. Implementing means satisfying the existing interface contract by writing the proscribed method bodies. Logically, when you extend an abstract class and fill in the method bodies, that should be called implementing too, but in the Java world that is called extending.
When you provide an abstract class to satisfy an interface, logically you have not really implemented anything, but in the Java world, that still counts as implementing.
When a class or abstract class implements or extends, those methods are are available in all descendants. All descendant classes automatically implement that interface too. You you can refer to descendant class objects by the base class name or the interface name.
available on the web at:
optional Replicator mirror
Please email your feedback for publication, letters to the editor, errors, omissions, typos, formatting errors, ambiguities, unclear wording, broken/redirected link reports, suggestions to improve this page or comments to Roedy Green : . If you want your message, your name or email kept confidential, not considered for public posting, please explicitly specify that. Unless you state otherwise, I will treat your message as a letter to the editor that I may or may not publish in the feedback section. After that, it will be too late to retract it. If you disagree with something I said, especially when sending an ad-hominem attack, a rant composed mainly of obscenities or a death threat, please quote the offending passage and cite the web page where you found it, tell me why you think it is wrong, and, if possible, provide some supporting evidence. I can’t very well fix erroneous or ambiguous text if I can’t find it.
Your face IP:[188.8.131.52]
|Feedback||You are visitor number 11.|