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Ternary Operator?Hi all, im just curious if anyone knows.....
With .NET 2, VB didnt happen to get a true ternary operator, did it? Stuck away in a corner somewhere? By ternary, i mean something like C's a?b:c syntax. IIf works in most cases, but in some instances you want to use expressions which may fail if they are evaluated when they arent supposed to be, and it would be nice to have a concise way of writing this instead of using a whole If-Then-Else block. Cheers all, - Arthur Dent. Arthur Dent wrote:
> Hi all, im just curious if anyone knows..... Perhaps you're looking for AndAlso and OrElse which do the evaluation > With .NET 2, VB didnt happen to get a true ternary operator, did it? > Stuck away in a corner somewhere? > By ternary, i mean something like C's a?b:c syntax. > IIf works in most cases, but in some instances you want to use > expressions which may fail if they are evaluated when they arent > supposed to be, and it would be nice to have a concise way of writing > this instead of using a whole If-Then-Else block. short-circuiting it sounds like you want. If False AndAlso thisNeverGetsCalled() then... If True OrElse thisNeverGetsCalled() then... Andrew Thanks for the tip.... i love the new short circuited booleans, but hadnt
thought of using them as ternary operatory replacements. Still not quite as elegent, but it will work better than a whole if-then-else block. Thanks! Show quoteHide quote "Andrew Morton" <a**@in-press.co.uk.invalid> wrote in message news:OVO7kkQTGHA.736@TK2MSFTNGP12.phx.gbl... > Arthur Dent wrote: >> Hi all, im just curious if anyone knows..... >> With .NET 2, VB didnt happen to get a true ternary operator, did it? >> Stuck away in a corner somewhere? >> By ternary, i mean something like C's a?b:c syntax. >> IIf works in most cases, but in some instances you want to use >> expressions which may fail if they are evaluated when they arent >> supposed to be, and it would be nice to have a concise way of writing >> this instead of using a whole If-Then-Else block. > > Perhaps you're looking for AndAlso and OrElse which do the evaluation > short-circuiting it sounds like you want. > > If False AndAlso thisNeverGetsCalled() then... > > If True OrElse thisNeverGetsCalled() then... > > Andrew > "Arthur Dent" <hitchhikersguideto-n***@yahoo.com> schrieb: VB's equivalent is> With .NET 2, VB didnt happen to get a true ternary operator, did it? Stuck > away in a corner somewhere? > By ternary, i mean something like C's a?b:c syntax. \\\ If x Then o = a Else o = b End If /// which can be written as 'If x Then o = a Else o = b'. -- M S Herfried K. Wagner M V P <URL:http://dotnet.mvps.org/> V B <URL:http://classicvb.org/petition/> Arthur,
I would not tell this as like C, it is more syntax from older spreadsheetprograms where everything had to be done in one cell.. Cor Show quoteHide quote "Arthur Dent" <hitchhikersguideto-n***@yahoo.com> schreef in bericht news:OBlyBIQTGHA.5496@TK2MSFTNGP11.phx.gbl... > Hi all, im just curious if anyone knows..... > With .NET 2, VB didnt happen to get a true ternary operator, did it? Stuck > away in a corner somewhere? > By ternary, i mean something like C's a?b:c syntax. > IIf works in most cases, but in some instances you want to use expressions > which may fail if they are evaluated when they arent supposed to be, and > it would be nice to have a concise way of writing this instead of using a > whole If-Then-Else block. > > Cheers all, > - Arthur Dent. > "Arthur Dent" <hitchhikersguideto-n***@yahoo.com> wrote in I think that IIf is still available:news:OBlyBIQTGHA.5496@TK2MSFTNGP11.phx.gbl: > By ternary, i mean something like C's a?b:c syntax. Return CStr(IIf(testMe > 1000, "Large", "Small")) It's in the help files. Is it deprecated for some reason? Tim F Tim,
| It's in the help files. Is it deprecated for some reason? IIf is not deprecated, however you need to be aware of how to use it!Its a function!!! Which means that both operands are evaluated. For example: Dim index As Integer = 1000 Dim list(100) as String Dim value As String = IIf(index < list.Length, list(index), "out of range") Will cause an index out of range exception as list(index) will be evaluated & passed to the IIf function, the function then returns either the true part of the false part... IIf has a couple of other "problems", its not Option Strict On friendly and it's parameters & return value are Object. In other words with Option Strict On, I would need to cast the return value above back to String. The parameters being Object, means that value types (structures) will be boxed & unboxed when you call IIf, which itself may be a slight performance problem and will add pressure to the GC... If your using .NET 2.0 I would recommend a Generic IIf instead: http://www.tsbradley.net/Cookbook/Generics/genericIIf.aspx My generic IIf avoids the Option Strict On & Object boxing problems, however its still a function. -- Show quoteHide quoteHope this helps Jay [MVP - Outlook] ..NET Application Architect, Enthusiast, & Evangelist T.S. Bradley - http://www.tsbradley.net "Tim Ferguson" <Ferguso***@softhome.net> wrote in message news:Xns978DBD59171C3garbleme4455656@207.46.248.16... | "Arthur Dent" <hitchhikersguideto-n***@yahoo.com> wrote in | news:OBlyBIQTGHA.5496@TK2MSFTNGP11.phx.gbl: | | > By ternary, i mean something like C's a?b:c syntax. | | I think that IIf is still available: | | Return CStr(IIf(testMe > 1000, "Large", "Small")) | | It's in the help files. Is it deprecated for some reason? | | Tim F | "Jay B. Harlow [MVP - Outlook]" <Jay_Harlow_***@tsbradley.net> wrote in Whoops: I knew that... teach me to read the question a bit more closely!news:#CCCNLbTGHA.5264@TK2MSFTNGP10.phx.gbl: > > Its a function!!! Which means that both operands are evaluated. > > B Wishes Tim F Right - there is no ternary operator.
IIf is clumsy for ther reasons you mention. The closest functional equivalent is If/Else blocks (but rather unwieldy for the kind of things you'd use the ternary operator for). -- Show quoteHide quoteDavid Anton www.tangiblesoftwaresolutions.com Instant C#: VB to C# converter Instant VB: C# to VB converter Instant C++: C# to C++ converter & VB to C++ converter Instant J#: VB to J# converter "Arthur Dent" wrote: > Hi all, im just curious if anyone knows..... > With .NET 2, VB didnt happen to get a true ternary operator, did it? Stuck > away in a corner somewhere? > By ternary, i mean something like C's a?b:c syntax. > IIf works in most cases, but in some instances you want to use expressions > which may fail if they are evaluated when they arent supposed to be, and it > would be nice to have a concise way of writing this instead of using a whole > If-Then-Else block. > > Cheers all, > - Arthur Dent. > > > Nice to hear someone who knows why i would want it. Most people usually say
"just use an if-then-else" which works, but is clumsy. At least i am not the only one who gets it. :) Show quoteHide quote "David Anton" <DavidAn***@discussions.microsoft.com> wrote in message news:97078DFA-E003-4275-BD7E-017E5141C83B@microsoft.com... > Right - there is no ternary operator. > IIf is clumsy for ther reasons you mention. > The closest functional equivalent is If/Else blocks (but rather unwieldy > for > the kind of things you'd use the ternary operator for). > -- > David Anton > www.tangiblesoftwaresolutions.com > Instant C#: VB to C# converter > Instant VB: C# to VB converter > Instant C++: C# to C++ converter & VB to C++ converter > Instant J#: VB to J# converter > > > > "Arthur Dent" wrote: > >> Hi all, im just curious if anyone knows..... >> With .NET 2, VB didnt happen to get a true ternary operator, did it? >> Stuck >> away in a corner somewhere? >> By ternary, i mean something like C's a?b:c syntax. >> IIf works in most cases, but in some instances you want to use >> expressions >> which may fail if they are evaluated when they arent supposed to be, and >> it >> would be nice to have a concise way of writing this instead of using a >> whole >> If-Then-Else block. >> >> Cheers all, >> - Arthur Dent. >> >> >> "Arthur Dent" <hitchhikersguideto-n***@yahoo.com> schrieb: 'If...Then...Else...' will some in many cases, but not in all. That's true.> Nice to hear someone who knows why i would want it. Most people usually > say "just use an if-then-else" which works, but is clumsy. -- M S Herfried K. Wagner M V P <URL:http://dotnet.mvps.org/> V B <URL:http://classicvb.org/petition/> "Herfried K. Wagner [MVP]" <hirf-spam-me-here@gmx.at> wrote in message Just use C#! :P And no, there is no terd...err...ternary operator ... news:Og7N%23$RTGHA.4300@TK2MSFTNGP14.phx.gbl... > "Arthur Dent" <hitchhikersguideto-n***@yahoo.com> schrieb: >> Nice to hear someone who knows why i would want it. Most people usually >> say "just use an if-then-else" which works, but is clumsy. > > 'If...Then...Else...' will some in many cases, but not in all. That's > true. > > -- > M S Herfried K. Wagner > M V P <URL:http://dotnet.mvps.org/> > V B <URL:http://classicvb.org/petition/> unfortunately...IIf is as close as you can get but is dangerous for obvious reasons. I wish there were ternary in VB.Net (as well as all other languages too!)... Mythran Mythran,
Maybe can you than use the Eval function and use JScript. http://www.vb-tips.com/default.aspx?ID=34241f3e-16ff-4e87-86d1-2b03e1a439ae I hope this helps, Cor lol:)
Show quoteHide quote "Cor Ligthert [MVP]" wrote: > Mythran, > > Maybe can you than use the Eval function and use JScript. > > http://www.vb-tips.com/default.aspx?ID=34241f3e-16ff-4e87-86d1-2b03e1a439ae > > I hope this helps, > > Cor > > > | I wish there were ternary in VB.Net (as well as all other I would like to see a true ternary operator in VB.NET, however I don't want | languages too!)... something as "obscure" as C's "a?b:c" I like the IIf syntax, however its a function, changing it to an actual inline operator may break code. (of course in many cases that breakage may actually be helping the code ;-)) -- Show quoteHide quoteHope this helps Jay [MVP - Outlook] ..NET Application Architect, Enthusiast, & Evangelist T.S. Bradley - http://www.tsbradley.net "Mythran" <kip_potter@hotmail.comREMOVETRAIL> wrote in message news:%23msjoEUTGHA.5808@TK2MSFTNGP12.phx.gbl... | | "Herfried K. Wagner [MVP]" <hirf-spam-me-here@gmx.at> wrote in message | news:Og7N%23$RTGHA.4300@TK2MSFTNGP14.phx.gbl... | > "Arthur Dent" <hitchhikersguideto-n***@yahoo.com> schrieb: | >> Nice to hear someone who knows why i would want it. Most people usually | >> say "just use an if-then-else" which works, but is clumsy. | > | > 'If...Then...Else...' will some in many cases, but not in all. That's | > true. | > | > -- | > M S Herfried K. Wagner | > M V P <URL:http://dotnet.mvps.org/> | > V B <URL:http://classicvb.org/petition/> | | Just use C#! :P And no, there is no terd...err...ternary operator ... | unfortunately...IIf is as close as you can get but is dangerous for obvious | reasons. I wish there were ternary in VB.Net (as well as all other | languages too!)... | | Mythran | i used to agree with you, but i must admit it ainitially looks clumsy but
If... stuff Else ....morestuff End If reads clearer than a ternary construct a year later regards Ford btw 42 = 6 x 9 in base 13 :)) Show quoteHide quote "Arthur Dent" wrote: > Hi all, im just curious if anyone knows..... > With .NET 2, VB didnt happen to get a true ternary operator, did it? Stuck > away in a corner somewhere? > By ternary, i mean something like C's a?b:c syntax. > IIf works in most cases, but in some instances you want to use expressions > which may fail if they are evaluated when they arent supposed to be, and it > would be nice to have a concise way of writing this instead of using a whole > If-Then-Else block. > > Cheers all, > - Arthur Dent. > > > |
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