WriteOnly

[Robert Surtees]

Maybe the property is part of a quantum computer and so write only to spare the possible life of a cat.

[The Cake of Deceit]

Robert Surtees wrote:

Maybe the property is part of a quantum computer and so write only to spare the possible life of a cat.

You would need 9 WriteOnly properties then. Remember; they have 9 lives! LOL. :laugh: (who would build a supercomputer in VB? the language is slightly crippled, but this WriteOnly thing gives a advantage over C# or the awful C++)

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[The Cake of Deceit]

Unless you do this: Public WriteOnly Property example As Object Set(ByVal value As Object) ' Do Nothing Here, Process Nothing Here End Set End Property

CLR: Removes tough Java-based stains fast!

[The Cake of Deceit]

But you do it manually. (and I think it complains.) CLR: Removes tough Java-based stains fast!

[Dave Kreskowiak]

Yes, I have SEEN the other side! Nothing much to see, it's pretty dark...

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Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
     2006, 2007, 2008

[CPallini]

I'm familiar, hence I'm going to write few lines explaining..., but, wait, maybe I'm too close to, s**t.................................... :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

[Vasudevan Deepak Kumar]

It is not a surprise, given that VB itself is a horror. :rolleyes:

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A pessimist sees only the dark side of the clouds, and mopes; a philosopher sees both sides, and shrugs; an optimist doesn't see the clouds at all - he's walking on them. --Leonard Louis Levinson

[The Cake of Deceit]

Dave Kreskowiak wrote:

Not quite. It turns a property into something akin to a voting box. You put your vote in, and there's no way to get it out.

But the Get accessor only returns it. Get does not remove the item.

CLR: Removes tough Java-based stains fast!

[Luc Pattyn]

Dave Kreskowiak wrote:

it's pretty dark...

are you sure? if it sucks everything in, and never lets go, it must be bloody light in there. :)

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[The Cake of Deceit]

Yes, it's a good language, but I prefer C#. Besides, WriteOnly is so weirdly funny! :laugh:

CLR: Removes tough Java-based stains fast!

[elektrowolf]

Alpha Nerd wrote:

Who would use it? A coding horror in VB.

In VB? In C#, too: class Foo { private int _val; public int Val { set { this._val = value; } } }

[Dr Walt Fair PE]

The best use for write-only things, in general, is when you are dealing with real-time control interfaces. Some devices allow you to save data to a memory location or port and that sets control bits in an external device. As far as the external device is concerned, it is an input-only deal; from the program's viewpoint it's write-only and any attempt to read would be undefined or return garbage. One logical use for a write-only property would be to control interfaces with external hardware. You would define a class encapsulating the hardware access and anything that writes to the hardware without any chance of being able to read the real-time results back, would logically be marked as WriteOnly. This is fairly common when using some PIC chips, DSP chips and assorted other devices. In my DSP applications, marking output data as WriteOnly would make perfect sense, since once it is sent to the buffer, it goes out the sound interface and does not exist anywhere that is accessible to the software. (Note: I haven't done that, since I knew it was essentially write-only and never thought I might try to read it again.) To me, marking a property as WriteOnly in a VB, C, C# or any other language very clearly tells everyone not to even bother to read it back because the data no longer exists. Another use for WriteOnly properties would be when dealing with highly asychronous processes, but I won't go into that here. So, yeah, if you're dealing with stuff in your own application's memory, WriteOnly may not make much sense, but if you are dealing with control systems and external devices, it may well make perfect sense.

The PetroNerd

Walt Fair, Jr. Comport Computing Specializing in Technical Engineering Software

[Dave Kreskowiak]

I think the light is processed into something else. I couldn't tell what though, because, like, there's no light! :-D

A guide to posting questions on CodeProject[^]
Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
     2006, 2007, 2008

[Luc Pattyn]

Aha, I see. Or actually maybe I don't, lacking some light??

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This month's tips: - before you ask a question here, search CodeProject, then Google; - the quality and detail of your question reflects on the effectiveness of the help you are likely to get; - use PRE tags to preserve formatting when showing multi-line code snippets.

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[PIEBALDconsult]

I suppose a write-only property (in whatever language, but preferably C#) could be used when defining something like a queue (Enqueue) or a stack (Push). (Though not recommended.)

[elektrowolf]

Full ACK. It's those little advantages of C# like anonymous delegates, lambda expressions without return value, automatic properties, a.s.o. that made me prefer C#. But one can't say VB is horrible! Basically, it has all features of C# and just an other syntax.

[Russell Jones]

writeonly properties are just as possible in c#, just create a property without an accessor. It's probably not great practice to use one but there may be times when it came in handy

[Lost User]

I quite often use write only properties in C# Consider this: Object A depends on an internal state and also needs an Object B for whatever it does. Object B inherits from a baseclass or interface, so there are many classes that may be used to create an instance to use as object B. Hardcoding it in A is not an option. Instead I use a write only property of A to pass a suitable object B at runtime. Object A then reinitializes it's internal state and prepares B for its use. I do not want to have access to object B anymore. It is not needed and indeed any tampering with B would have a bearing on A's state. With a write only property this problem cannot arise.

[Mr PoorEnglish]

MarkBrock wrote:

VB itself is a coding horror.

maybe the greatest advantage to VB is that the programmers aren't as arrogant as C# programmers. (otherwise: the meaning of writeonly also is a secret for me.)

[MarkB777]

haha I don't think any of the "anti-VB"'ers in here are really serious about what they say. I've worked on a very large VB.NET project as well - A customized CMS for our government. People are just taking the piss. ;)

Mark Brock Click here to view my blog