William Hindman
wdhindman at dejpolsystems.com
Wed Feb 25 17:17:21 CST 2009
...yes and no ...multiple inheritance ala c++ is not possible but dotnet does support multiple interface inheritance which gets you a good long way down the road :) ...btw, I'm a flounderer and quite accepting of it ...I just keep on keeping on :) William -------------------------------------------------- From: "jwcolby" <jwcolby at colbyconsulting.com> Sent: Wednesday, February 25, 2009 5:57 PM To: "Access Developers discussion and problem solving" <accessd at databaseadvisors.com> Subject: Re: [AccessD] Class costs & benefits > William, > > AFAIK multiple inheritance is not possible in .Net either right? > > So yes, inheritance is a really cool feature, and it does not exist in > Access. > > OTOH, even in .Net there are things that you want to program that don't > inherit from anything. > Business class objects come to mind. > > I'll tell you a little story. > > When I was in Mexico I was worked on a vending machine project, broken > into three parts. There was > a database in a handheld computer, written in Foxpro for DOS (no > inheritance). There was a database > on the desktop written in FoxPro for Windows which had inheritance, and > there was the vending > machine itself (my part) written in C running on a ZWorld z80 based uC. > The HH code was written and > debugged. The vending machine code was written and debugged. The desktop > db was hopelessly bogged > down in discussions on what should be inheriting what base stuff, what > should be inheriting from the > stuff that they managed to write etc. It was fascinating to sit at the > edges of and watch. > > Now... this was mid 90s and I guess that the inheritance thing was new to > these guys but the point > remains that inheritance is a double edged sword. Once you understand and > can correctly and quickly > make such choices, it can be very powerful. Until that point you can > flounder around a lot... > > I do agree that the .Net framework is one of the most powerful frameworks > I have ever seen. Nothing > short of awesome IMHO. > > John W. Colby > www.ColbyConsulting.com > > > William Hindman wrote: >> ...ok ...a basic view ...the real value comes when you can inherit from >> more >> than one object and you can pick and choose what you inherit ...within >> reason, you can build practically anything without having to start from >> scratch ...VS gives you some basic tools, a grid for instance ...and you >> can >> go a long time before it dawns on you that you don't have to accept that >> basic grid ...you can reach back in the object hierarchy and build a grid >> that does what YOU need ...a treeview with a grid node for instance >> ...all >> without having to lay out bucks for third party tools that only do half >> of >> what you wanted. >> >> ...to me, that's the real value of working with dot net ...there is >> sooooo >> much built in high level stuff that lets you easily build low level >> custom >> objects for your apps ...and sooooooo many blogs out there with guys >> doing >> highly creative things that its nigh impossible to keep up. >> >> William >> >> -------------------------------------------------- >> From: "jwcolby" <jwcolby at colbyconsulting.com> >> Sent: Wednesday, February 25, 2009 4:14 PM >> To: "Access Developers discussion and problem solving" >> <accessd at databaseadvisors.com> >> Subject: Re: [AccessD] Class costs & benefits >> >>> The simplest illustration is to say that inheritance is the ability to >>> define your own object as >>> starting from something already in existence. >>> >>> Inheritance in the programming world mimics inheritance in the genetic >>> world except that in most >>> languages you are only allowed to inherit properties from a single >>> parent. >>> >>> So. I am my dad. I get everything my dad has, his eyes, his height, >>> his >>> race, his ... >>> >>> I add to what I inherited. >>> >>> I add a bunch of extra pounds. I add the experience of living in Mexico >>> for five years. I add the >>> knowledge of building computers. >>> >>> In programming. I inherit a text control. I add code to check my >>> control >>> source to see what data >>> type it is. I then add new method to make my display format depend on >>> the >>> data type I am bound to. >>> >>> I have all of the normal properties of a text box. I can generate all >>> of >>> the events that the text >>> box generated. But I have additional code to check my data type and >>> format myself differently >>> depending on the data type. And other useful things. >>> >>> That in a nutshell is inheritance. >>> >>> Access does not have inheritance. That doesn't Accesses classes useless >>> however. A class is far >>> more than the ability to inherit another object, even in languages where >>> inheritance is possible. >>> >>> John W. Colby >>> www.ColbyConsulting.com >>> >>> >>> Rocky Smolin at Beach Access Software wrote: >>>> "I will promise to treat every opinion as valid and not go into rant >>>> mode. >>>> ;)" Gonna be a pretty dull thread. >>>> >>>> For those of who don't know, can you define inheritance? >>>> >>>> >>>> Rocky Smolin >>>> Beach Access Software >>>> 858-259-4334 >>>> www.e-z-mrp.com >>>> www.bchacc.com >>>> >>>> >>>> >>>> -----Original Message----- >>>> From: accessd-bounces at databaseadvisors.com >>>> [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of jwcolby >>>> Sent: Wednesday, February 25, 2009 7:48 AM >>>> To: Access Developers discussion and problem solving >>>> Subject: [AccessD] Class costs & benefits >>>> >>>> From Rocky's email I thought that perhaps a thread on what the costs >>>> and >>>> benefits are for classes. >>>> >>>> Jim made a statement that he felt that "Access has no implementation >>>> inheritance and since inheritance really is the whole point of using >>>> classes, I think they are more or less a waste in Access". >>>> >>>> So what are your feelings and opinions about classes? >>>> >>>> I will promise to treat every opinion as valid and not go into rant >>>> mode. >>>> ;) >>>> >>>> In fact I will promise to not respond to any message unless the author >>>> specifically asks me to for some reason. >>>> >>>> -- >>>> John W. Colby >>>> www.ColbyConsulting.com >>>> -- >>>> AccessD mailing list >>>> AccessD at databaseadvisors.com >>>> http://databaseadvisors.com/mailman/listinfo/accessd >>>> Website: http://www.databaseadvisors.com >>>> >>> -- >>> AccessD mailing list >>> AccessD at databaseadvisors.com >>> http://databaseadvisors.com/mailman/listinfo/accessd >>> Website: http://www.databaseadvisors.com >>> >> > -- > AccessD mailing list > AccessD at databaseadvisors.com > http://databaseadvisors.com/mailman/listinfo/accessd > Website: http://www.databaseadvisors.com >