| Groups | Blog | Home |
c# : C# Switch statement
[quoted text, click to view]
"Duncan McNutt [BSDM]" <nutmaster@127.0.0.66> wrote: > Is it possible to have ranges or patterns in a case ? > > If not, why wasnt this designed in to make it easier instead of listing > every case value needed? You should get a beginner's C# book and start reading it. --
Is it possible to have ranges or patterns in a case ?
If not, why wasnt this designed in to make it easier instead of listing every case value needed? -- Duncan McNutt Microsoft Product Deactivation Team --
I am trying to install MIS 2002 Trial I downloaded from the MS site but I
get the following errors. How can I fix this and get it installing? Any ideas? Event Type: Error Event Source: MsiInstaller Event Category: None Event ID: 11720 Date: 8/17/2003 Time: 10:09:38 PM User: N/A Computer: VMWARE2KPRO Description: Product: Mobile Information Server -- Error 1720.There is a problem with this Windows Installer package. A script required for this install to complete could not be run. Contact your support personnel or package vendor. Custom action IsDCLogon script error -2147023665, : Line 2339, Column 5, -- Duncan McNutt Microsoft Product Deactivation Team -- [quoted text, click to view] "Harry Bosch" <none@given.com> wrote in message news:Xns93DA899A21702hboschsbc@207.46.248.16... > "Duncan McNutt [BSDM]" <nutmaster@127.0.0.66> wrote: > > > Is it possible to have ranges or patterns in a case ? > > > > If not, why wasnt this designed in to make it easier instead of listing > > every case value needed? > > You should get a beginner's C# book and start reading it. > > -- > harry
oops, wrong thread.
-- Duncan McNutt Microsoft Product Deactivation Team -- [quoted text, click to view] "Duncan McNutt .[BSDM]" <mutmaster@127.0.0.22> wrote in message news:uhr1Y7PZDHA.388@TK2MSFTNGP10.phx.gbl... > I am trying to install MIS 2002 Trial I downloaded from the MS site but I > get the following errors. > > How can I fix this and get it installing? Any ideas? > > Event Type: Error > Event Source: MsiInstaller > Event Category: None > Event ID: 11720 > Date: 8/17/2003 > Time: 10:09:38 PM > User: N/A > Computer: VMWARE2KPRO > Description: > Product: Mobile Information Server -- Error 1720.There is a problem with > this Windows Installer package. A script required for this install to > complete could not be run. Contact your support personnel or package vendor. > Custom action IsDCLogon script error -2147023665, : Line 2339, Column 5, > > -- > > Duncan McNutt > Microsoft Product Deactivation Team > -- > > > > "Harry Bosch" <none@given.com> wrote in message > news:Xns93DA899A21702hboschsbc@207.46.248.16... > > "Duncan McNutt [BSDM]" <nutmaster@127.0.0.66> wrote: > > > > > Is it possible to have ranges or patterns in a case ? > > > > > > If not, why wasnt this designed in to make it easier instead of listing > > > every case value needed? > > > > You should get a beginner's C# book and start reading it. > > > > -- > > harry > >
I love C#. But I strongly disagree with M$ C# team on the design of the
switch-break statement. C# does not allow automatic fall through for each case statement, yet it requires a mandatory and useless break statement. It's completely insane to have such a design. The break statement is compeletely NOT NECESSARY! I understand they want to make programmers make LESS errors by breaking C/C++ goodness (e.g., range of values). But those errors caused by case-break pair never get in my way throughout 8 years of C/C++ programming experience. Actually I've never made a mistake when coding case-break's. I think they might want to give a compiler warning when there is no break statement after a case statement. That's the best way keeping C/C++ goodness yet giving programmers much, much less chance for making errors. Edward [quoted text, click to view] "Duncan McNutt [BSDM]" <nutmaster@127.0.0.66> wrote in message news:eNPUQtPZDHA.2352@TK2MSFTNGP12.phx.gbl... > Is it possible to have ranges or patterns in a case ? > > If not, why wasnt this designed in to make it easier instead of listing > every case value needed? > > -- > > Duncan McNutt > Microsoft Product Deactivation Team > -- > > > >
OMG, I thought it is not allowed to do this!
I read MSDN again, and find this: Although fall through from one case label to another is not supported, it is allowed to stack case labels, for example: case 0: case 1: // do something; Edward [quoted text, click to view] "Stan" <stanly12spamremove@yahoo.com.au> wrote in message news:eFxvT3RZDHA.652@tk2msftngp13.phx.gbl... > Here, I did a search and copied one of the many replies to this common > question. > > > > Yes, like this: > > using System; > > class Test > { > > public static void Main() > { > int x; > x=Convert.ToInt16(Console.ReadLine()); > switch (x) > { > case 1: > case 2: > case 3: > Console.WriteLine("Is 1 2 3"); > break; > case 4: > case 5: > case 6: > Console.WriteLine("Is 4 5 6"); > break; > default: > Console.WriteLine("Is greater than 6"); > break; > } > } > } > > However, you can't do greater than/less than (i.e. case 4 to 6) like > you could do in VB. You'll have to use if/else statements for that. > > 'Lib > > > > "Duncan McNutt [BSDM]" <nutmaster@127.0.0.66> wrote in message > news:eNPUQtPZDHA.2352@TK2MSFTNGP12.phx.gbl... > > Is it possible to have ranges or patterns in a case ? > > > > If not, why wasnt this designed in to make it easier instead of listing > > every case value needed? > > > > -- > > > > Duncan McNutt > > Microsoft Product Deactivation Team > > -- > > > > > > > > > >
Sorry, I want to correct a small part of my comment. See Stan's reply in
this thread above this post. C# does allow the old way of 'stacking' case's. <msdn> Although fall through from one case label to another is not supported, it is allowed to stack case labels, for example: case 0: case 1: // do something; </msdn> But do not put any code (comment is OK) after case 0 or case 1, otherwise the non-fall-through compiler error will get you. Edward [quoted text, click to view] "Edward Yang" <neo_in_matrix@msn.com> wrote in message news:%23MRWNcSZDHA.1620@TK2MSFTNGP12.phx.gbl... > I love C#. But I strongly disagree with M$ C# team on the design of the > switch-break statement. > > C# does not allow automatic fall through for each case statement, yet it > requires a mandatory and useless break statement. It's completely insane to > have such a design. The break statement is compeletely NOT NECESSARY! > > I understand they want to make programmers make LESS errors by breaking > C/C++ goodness (e.g., range of values). But those errors caused by > case-break pair never get in my way throughout 8 years of C/C++ programming > experience. Actually I've never made a mistake when coding case-break's. > > I think they might want to give a compiler warning when there is no break > statement after a case statement. That's the best way keeping C/C++ goodness > yet giving programmers much, much less chance for making errors. > > Edward > > > "Duncan McNutt [BSDM]" <nutmaster@127.0.0.66> wrote in message > news:eNPUQtPZDHA.2352@TK2MSFTNGP12.phx.gbl... > > Is it possible to have ranges or patterns in a case ? > > > > If not, why wasnt this designed in to make it easier instead of listing > > every case value needed? > > > > -- > > > > Duncan McNutt > > Microsoft Product Deactivation Team > > -- > > > > > > > > > >
Here, I did a search and copied one of the many replies to this common
question. [quoted text, click to view] > Yes, like this: using System; class Test { public static void Main() { int x; x=Convert.ToInt16(Console.ReadLine()); switch (x) { case 1: case 2: case 3: Console.WriteLine("Is 1 2 3"); break; case 4: case 5: case 6: Console.WriteLine("Is 4 5 6"); break; default: Console.WriteLine("Is greater than 6"); break; } } } However, you can't do greater than/less than (i.e. case 4 to 6) like you could do in VB. You'll have to use if/else statements for that. 'Lib [quoted text, click to view] "Duncan McNutt [BSDM]" <nutmaster@127.0.0.66> wrote in message news:eNPUQtPZDHA.2352@TK2MSFTNGP12.phx.gbl... > Is it possible to have ranges or patterns in a case ? > > If not, why wasnt this designed in to make it easier instead of listing > every case value needed? > > -- > > Duncan McNutt > Microsoft Product Deactivation Team > -- > > > >
It's a feature vs. complexity thing.. While we agree that there are cases
where case ranges are useful, we don't think that their usefullness above what you get with a simple series of if statements outweighs the increase in complexity. -- Eric Gunnerson Visit the C# product team at http://www.csharp.net Eric's blog is at http://blogs.gotdotnet.com/ericgu/ This posting is provided "AS IS" with no warranties, and confers no rights. [quoted text, click to view] "Duncan McNutt [BSDM]" <nutmaster@127.0.0.66> wrote in message news:eNPUQtPZDHA.2352@TK2MSFTNGP12.phx.gbl... > Is it possible to have ranges or patterns in a case ? > > If not, why wasnt this designed in to make it easier instead of listing > every case value needed? > > -- > > Duncan McNutt > Microsoft Product Deactivation Team > -- > > > >
[quoted text, click to view]
> experience. Actually I've never made a mistake when coding case-break's. Bullshit. -- Michael Culley
On Mon, 18 Aug 2003 13:23:33 -0700, "Eric Gunnerson [MS]"
[quoted text, click to view] <ericgu@online.microsoft.com> wrote: >It's a feature vs. complexity thing.. While we agree that there are cases >where case ranges are useful, we don't think that their usefullness above >what you get with a simple series of if statements outweighs the increase in >complexity. I agree. However, what about adding syntax like this: switch (num) { case 1 to 5: //code break; } and translate it to the appropriate IL as if it were written like: switch (num) { case 1: case 2: case 3: case 4: case 5: //code break; } As this allows increased readability and is easily maintainable? Thanks,
Complexity for whom?
-- Duncan McNutt Microsoft Product Deactivation Team -- [quoted text, click to view] "Eric Gunnerson [MS]" <ericgu@online.microsoft.com> wrote in message news:ePk$macZDHA.2336@TK2MSFTNGP09.phx.gbl... > It's a feature vs. complexity thing.. While we agree that there are cases > where case ranges are useful, we don't think that their usefullness above > what you get with a simple series of if statements outweighs the increase in > complexity. > > -- > Eric Gunnerson > > Visit the C# product team at http://www.csharp.net > Eric's blog is at http://blogs.gotdotnet.com/ericgu/ > > This posting is provided "AS IS" with no warranties, and confers no rights. > "Duncan McNutt [BSDM]" <nutmaster@127.0.0.66> wrote in message > news:eNPUQtPZDHA.2352@TK2MSFTNGP12.phx.gbl... > > Is it possible to have ranges or patterns in a case ? > > > > If not, why wasnt this designed in to make it easier instead of listing > > every case value needed? > > > > -- > > > > Duncan McNutt > > Microsoft Product Deactivation Team > > -- > > > > > > > > > >
So a little thing like that that may aid code readability is not good but
adding crap like Lambada functions (anonymous methods) and partial types ( to aid splitting source files) that is good? You have the BCLs make an entire pigs mess of VSplits and HSplits and you say thats good? Yet adding a simple thing like ranges into a case in the switch construct is bad because you cant be assed to handle the complexity? Pass the bong. -- Duncan McNutt Microsoft Product Deactivation Team -- [quoted text, click to view] "Eric Gunnerson [MS]" <ericgu@online.microsoft.com> wrote in message news:ePk$macZDHA.2336@TK2MSFTNGP09.phx.gbl... > It's a feature vs. complexity thing.. While we agree that there are cases > where case ranges are useful, we don't think that their usefullness above > what you get with a simple series of if statements outweighs the increase in > complexity. > > -- > Eric Gunnerson > > Visit the C# product team at http://www.csharp.net > Eric's blog is at http://blogs.gotdotnet.com/ericgu/ > > This posting is provided "AS IS" with no warranties, and confers no rights. > "Duncan McNutt [BSDM]" <nutmaster@127.0.0.66> wrote in message > news:eNPUQtPZDHA.2352@TK2MSFTNGP12.phx.gbl... > > Is it possible to have ranges or patterns in a case ? > > > > If not, why wasnt this designed in to make it easier instead of listing > > every case value needed? > > > > -- > > > > Duncan McNutt > > Microsoft Product Deactivation Team > > -- > > > > > > > > > >
That is complex??
But theyre adding Lambada funtions (anonymous methods) and Partial types!!! Thats even MORE complex and POINTLESS !!! -- Duncan McNutt Microsoft Product Deactivation Team -- [quoted text, click to view] "Austin Ehlers" <the*remove*bored*me*guy16@hotmail.com> wrote in message news:h043kv4cei6lnn03r7lrdd71kfl9r7d83n@4ax.com... > On Mon, 18 Aug 2003 13:23:33 -0700, "Eric Gunnerson [MS]" > <ericgu@online.microsoft.com> wrote: > > >It's a feature vs. complexity thing.. While we agree that there are cases > >where case ranges are useful, we don't think that their usefullness above > >what you get with a simple series of if statements outweighs the increase in > >complexity. > > I agree. However, what about adding syntax like this: > > switch (num) > { > case 1 to 5: > //code > break; > } > > and translate it to the appropriate IL as if it were written like: > > switch (num) > { > case 1: > case 2: > case 3: > case 4: > case 5: > //code > break; > } > > As this allows increased readability and is easily maintainable? > > Thanks, > Austin Ehlers
Amen.
[quoted text, click to view] "Austin Ehlers" <the*remove*bored*me*guy16@hotmail.com> wrote in message news:h043kv4cei6lnn03r7lrdd71kfl9r7d83n@4ax.com... > On Mon, 18 Aug 2003 13:23:33 -0700, "Eric Gunnerson [MS]" > <ericgu@online.microsoft.com> wrote: > > >It's a feature vs. complexity thing.. While we agree that there are cases > >where case ranges are useful, we don't think that their usefullness above > >what you get with a simple series of if statements outweighs the increase in > >complexity. > > I agree. However, what about adding syntax like this: > > switch (num) > { > case 1 to 5: > //code > break; > } > > and translate it to the appropriate IL as if it were written like: > > switch (num) > { > case 1: > case 2: > case 3: > case 4: > case 5: > //code > break; > } > > As this allows increased readability and is easily maintainable? > > Thanks, > Austin Ehlers
Both partial types and anonymous methods allow us to deal with situations
where C# does not work very well, and therefore the benefit that they bring is higher than the benefit that case ranges would bring. Partial types will let us segregate Windows Forms code into designer-generated code and user code. That will make the model much easier. There are other scenarios, but that's the primary one. Anonymous methods are very useful in a case where you need a small bit of code to pass as a delegate. If you put it in a separate method, you end up with a disconnect between the small bit of code and where it's actually used, which makes it harder to understand what's going on. If used for scenarios such as this, anonymous methods will make your code more readable. There is the chance for abuse with both features. -- Eric Gunnerson Visit the C# product team at http://www.csharp.net Eric's blog is at http://blogs.gotdotnet.com/ericgu/ This posting is provided "AS IS" with no warranties, and confers no rights. [quoted text, click to view] "Duncan McNutt [FTSE]." <futmaster@127.0.0.707> wrote in message news:OdbkV5cZDHA.1740@TK2MSFTNGP10.phx.gbl... > So a little thing like that that may aid code readability is not good but > adding crap like Lambada functions (anonymous methods) and partial types ( > to aid splitting source files) that is good? > > You have the BCLs make an entire pigs mess of VSplits and HSplits and you > say thats good? > > Yet adding a simple thing like ranges into a case in the switch construct is > bad because you cant be assed to handle the complexity? > > Pass the bong. > > > -- > > Duncan McNutt > Microsoft Product Deactivation Team > -- > > > "Eric Gunnerson [MS]" <ericgu@online.microsoft.com> wrote in message > news:ePk$macZDHA.2336@TK2MSFTNGP09.phx.gbl... > > It's a feature vs. complexity thing.. While we agree that there are cases > > where case ranges are useful, we don't think that their usefullness above > > what you get with a simple series of if statements outweighs the increase > in > > complexity. > > > > -- > > Eric Gunnerson > > > > Visit the C# product team at http://www.csharp.net > > Eric's blog is at http://blogs.gotdotnet.com/ericgu/ > > > > This posting is provided "AS IS" with no warranties, and confers no > rights. > > "Duncan McNutt [BSDM]" <nutmaster@127.0.0.66> wrote in message > > news:eNPUQtPZDHA.2352@TK2MSFTNGP12.phx.gbl... > > > Is it possible to have ranges or patterns in a case ? > > > > > > If not, why wasnt this designed in to make it easier instead of listing > > > every case value needed? > > > > > > -- > > > > > > Duncan McNutt > > > Microsoft Product Deactivation Team > > > -- > > > > > > > > > > > > > > > > > >
I'd have to see some actual code to understand how common this was and
whether it made sense to have a syntax for it. If it were only cases 1 - 5, you'd obviously write it with a single-clause if. If there are a lot more cases, I might be persuaded that it would be clearer to have a range. It would take a fair bit of data to understand what people were really doing and what the result of a new feature would be. My experience is that switch statements are fairly rare in OO code. -- Eric Gunnerson Visit the C# product team at http://www.csharp.net Eric's blog is at http://blogs.gotdotnet.com/ericgu/ This posting is provided "AS IS" with no warranties, and confers no rights. [quoted text, click to view] "Austin Ehlers" <the*remove*bored*me*guy16@hotmail.com> wrote in message news:h043kv4cei6lnn03r7lrdd71kfl9r7d83n@4ax.com... > On Mon, 18 Aug 2003 13:23:33 -0700, "Eric Gunnerson [MS]" > <ericgu@online.microsoft.com> wrote: > > >It's a feature vs. complexity thing.. While we agree that there are cases > >where case ranges are useful, we don't think that their usefullness above > >what you get with a simple series of if statements outweighs the increase in > >complexity. > > I agree. However, what about adding syntax like this: > > switch (num) > { > case 1 to 5: > //code > break; > } > > and translate it to the appropriate IL as if it were written like: > > switch (num) > { > case 1: > case 2: > case 3: > case 4: > case 5: > //code > break; > } > > As this allows increased readability and is easily maintainable? > > Thanks, > Austin Ehlers
Don't see what you're looking for? Try a search.
|
June 2003
July 2003
August 2003
September 2003
October 2003
November 2003
December 2003
January 2004
February 2004
March 2004
April 2004
May 2004
June 2004
July 2004
August 2004
September 2004
October 2004
November 2004
December 2004
January 2005
February 2005
March 2005
April 2005
May 2005
June 2005
July 2005
August 2005
September 2005
October 2005
November 2005
December 2005
January 2006
February 2006
March 2006
April 2006
May 2006
June 2006
July 2006
August 2006
September 2006
October 2006
November 2006
December 2006
January 2007
February 2007
March 2007
April 2007
May 2007
June 2007
July 2007
August 2007
September 2007
October 2007
November 2007
December 2007
January 2008
February 2008
March 2008
April 2008
| home · blog · groups | Questions? Comments? Contact the dn |