× The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.



Joe,

Good example.

Might be improved by considering the "pseudo" DLTOBJ command, DEL (aka RMVLNK).

Lastly, and hopefully not to confuse the issue. But Dr. Soltis points out the OS/400 is Object-Based
not Object-Oriented. The difference is Object-Based doesn't use inheritance (and thus doesn't use
polymorphism).

But that doesn't mean polymorphic behavior from the user perspective can't be simulated. As we see in
OS/400 or even our own RPG programs.

If OS/400 was Object-Oriented, we could define our own object types and the DEL command would work
just fine on them.

Charles


-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Joe Pluta
Sent: Friday, October 19, 2007 10:21 AM
To: 'RPG programming on the AS400 / iSeries'
Subject: Objects and such

I think, though, that sometimes we get blinded by
terminology. The idea of polymorphism is really pretty
simple, and we do it all the time, especially on the System i:

DLTF, DLTCMD, DLTPGM

If you think of these in object terms, they're really:

F.DLT, CMD.DLT, PGM.DLT

That is, you're sending the "DLT" message to the "F" object.
Move to the world of lower case and no abbreviations and you get:

File.delete, Command.delete, Program.delete

What does this say? It actually says two things. First, it
says that for each of these object types (or "classes" in
Java terminology) there is a delete method that can be
called. Different things will happen depending on which
object type you're deleting.

More importantly, though, it says that you can delete an
object represented by the File class by executing its delete
method, and that you can do the same for Command and for
Program. So finally:

myFile.delete(), myCommand.delete(), myProgram.delete()

This is the essence of polymorphism: call the same method for
different objects and the underlying code will do what it's
supposed to do.

To me, it's less an issue of understanding the concept than
it is of the syntax.

DLTCMD CMD(MYCMD) vs. myCommand.delete()


Joe


--
This is the RPG programming on the AS400 / iSeries (RPG400-L)
mailing list To post a message email: RPG400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/rpg400-l
or email: RPG400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/rpg400-l.




This e-mail transmission contains information that is intended to be confidential and privileged. If you receive this e-mail and you are not a named addressee you are hereby notified that you are not authorized to read, print, retain, copy or disseminate this communication without the consent of the sender and that doing so is prohibited and may be unlawful. Please reply to the message immediately by informing the sender that the message was misdirected. After replying, please delete and otherwise erase it and any attachments from your computer system. Your assistance in correcting this error is appreciated.


As an Amazon Associate we earn from qualifying purchases.

This thread ...

Follow-Ups:

Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].

Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.