Using GOTO

[Kartic]

Hi,
Is it good practice using GOTO in .NET application?

Please advice.

Thanks, Kartic

[Robin Tucker]

I'm not religious about it, although I don't have a single GOTO in over
50,000 lines of code in my project. It isn't neccessary. But if you feel
the need, be my guest ;)
"Kartic" <kg****@csystem ssoftware.com> wrote in message
news:uC******** ******@TK2MSFTN GP12.phx.gbl...

Hi,
Is it good practice using GOTO in .NET application?

Please advice.

Thanks, Kartic

[Cor Ligthert]

Hi Kartic,

Is this serious or do you want to build a long thread in this newsgroup.

The answer is No.

Cor

[William Ryan eMVP]

Kartic:

There are a few situations where Goto may be the best solution, like in a
switch statement where you want to simulate fall-through. However, those
situations are Rare indeed and I can count them on my hand. The real
problem with Goto is that people overuse them and use them as slopppy
shortcuts. Like Robin, I think in about 60,000 lines of code, I don't think
I've ever needed to use one, and prefer not to. And my examples of
Fall-through is related to C# mainly and only deals with switch statements.

Basically, the answer is No, don't use it. If you are absolutely sure that
using GoTo is the most effecitve way to do something, then go ahead, but
limit it's use as much as possible and make sure you have a very compelling
reason to use it. And if your program uses it more than once or twice in
rare occassions, you are already overusing it.

I'm not religious about it either, I just don't see much of a need for it...
and I've seen a lot more damage done with it than good come from it.
"Kartic" <kg****@csystem ssoftware.com> wrote in message
news:uC******** ******@TK2MSFTN GP12.phx.gbl...

Hi,
Is it good practice using GOTO in .NET application?

Please advice.

Thanks, Kartic

[Jay B. Harlow [MVP - Outlook]]

Kartic,
As the others suggest, most developers feel using GOTO is not a good
practice in any language!

However! using GOTO is useful sometimes.

One place I see value is a Try/Catch block to allow retrying a statement,
something like:

Try
TRYAGAIN:
AttemptToReadFi le()
' Throw New System.IO.FileN otFoundExceptio n
Catch ex As System.IO.FileN otFoundExceptio n
If MessageBox.Show ("What would you like to do?", "File not
found", MessageBoxButto ns.RetryCancel, MessageBoxIcon. Question,
MessageBoxDefau ltButton.Button 2) = DialogResult.Re try Then
GoTo TRYAGAIN
Else
Throw ' let error propagate up
End If
End Try

Where the AttemptToReadFi le method opens a file and attempts to read it, if
the file is not found, a dialog is shown to the user, and the Goto allows
the program to try the AttemptToReadFi le a second time. I would only handle
specific exceptions this way, for example FileNotFoundExc eption instead of
System.Exceptio n.
Another place I see value is in complicated loops, within loops, when you
need to get out of an inner most loop, back to the outer most loop quickly,
however I attempt to avoid nesting loops (directly) too much...

Hope this helps
Jay

"Kartic" <kg****@csystem ssoftware.com> wrote in message
news:uC******** ******@TK2MSFTN GP12.phx.gbl...

Hi,
Is it good practice using GOTO in .NET application?

Please advice.

Thanks, Kartic

[Robin Tucker]

Yes, the second example is one I've come across a lot in my code. Instead
of using the GOTO, I tend to use a boolean flag to tell me when to break out
of the loop. Actually, in this case, I would hardly say it was easier to
read or understand the flow of code, but I've just become used to doing
things like this rather than using gotos'.

"Jay B. Harlow [MVP - Outlook]" <Ja************ @msn.com> wrote in message
news:eC******** ******@TK2MSFTN GP12.phx.gbl...

Kartic,
As the others suggest, most developers feel using GOTO is not a good
practice in any language!

However! using GOTO is useful sometimes.

One place I see value is a Try/Catch block to allow retrying a statement,
something like:

Try
TRYAGAIN:
AttemptToReadFi le()
' Throw New System.IO.FileN otFoundExceptio n
Catch ex As System.IO.FileN otFoundExceptio n
If MessageBox.Show ("What would you like to do?", "File not
found", MessageBoxButto ns.RetryCancel, MessageBoxIcon. Question,
MessageBoxDefau ltButton.Button 2) = DialogResult.Re try Then
GoTo TRYAGAIN
Else
Throw ' let error propagate up
End If
End Try

Where the AttemptToReadFi le method opens a file and attempts to read it, if the file is not found, a dialog is shown to the user, and the Goto allows
the program to try the AttemptToReadFi le a second time. I would only handle specific exceptions this way, for example FileNotFoundExc eption instead of
System.Exceptio n.
Another place I see value is in complicated loops, within loops, when you
need to get out of an inner most loop, back to the outer most loop quickly, however I attempt to avoid nesting loops (directly) too much...

Hope this helps
Jay

"Kartic" <kg****@csystem ssoftware.com> wrote in message
news:uC******** ******@TK2MSFTN GP12.phx.gbl...

Hi,
Is it good practice using GOTO in .NET application?

Please advice.

Thanks, Kartic

[Cor Ligthert]

Hi Jay B. (And Bill)

I never come with documents, however this greath Dutchman will turn around
about your writting.

(He has done very much for modern programming, in my idea most modern
languages derives partialy from his ideas)

http://www.cs.utexas.edu/users/EWD/

http://www.acm.org/classics/oct95/

Cor

[Jay B. Harlow [MVP - Outlook]]

Robin,
Agreed.

I would consider the Boolean over the Goto, until the Boolean was
complicating & convoluting the code too much... In that there is stuff after
the inner loops that need to be skipped, so you have to include the Boolean
on each loop, then you need if statements that check the Boolean, then you
need...
Remember bad use of a Goto does not make the Goto bad!

Too many developers think Goto is Bad! as they have seen bad uses of Goto
too often...

Jay

"Robin Tucker" <id************ *************@r eallyidont.com> wrote in
message news:c6******** ***********@new s.demon.co.uk.. .

Yes, the second example is one I've come across a lot in my code. Instead
of using the GOTO, I tend to use a boolean flag to tell me when to break out of the loop. Actually, in this case, I would hardly say it was easier to
read or understand the flow of code, but I've just become used to doing
things like this rather than using gotos'.

"Jay B. Harlow [MVP - Outlook]" <Ja************ @msn.com> wrote in message
news:eC******** ******@TK2MSFTN GP12.phx.gbl...

Kartic,
As the others suggest, most developers feel using GOTO is not a good
practice in any language!

However! using GOTO is useful sometimes.

One place I see value is a Try/Catch block to allow retrying a statement, something like:

Try
TRYAGAIN:
AttemptToReadFi le()
' Throw New System.IO.FileN otFoundExceptio n
Catch ex As System.IO.FileN otFoundExceptio n
If MessageBox.Show ("What would you like to do?", "File not
found", MessageBoxButto ns.RetryCancel, MessageBoxIcon. Question,
MessageBoxDefau ltButton.Button 2) = DialogResult.Re try Then
GoTo TRYAGAIN
Else
Throw ' let error propagate up
End If
End Try

Where the AttemptToReadFi le method opens a file and attempts to read it,

if

the file is not found, a dialog is shown to the user, and the Goto allows the program to try the AttemptToReadFi le a second time. I would only

handle

specific exceptions this way, for example FileNotFoundExc eption instead of System.Exceptio n.
Another place I see value is in complicated loops, within loops, when you need to get out of an inner most loop, back to the outer most loop

quickly,

however I attempt to avoid nesting loops (directly) too much...

Hope this helps
Jay

"Kartic" <kg****@csystem ssoftware.com> wrote in message
news:uC******** ******@TK2MSFTN GP12.phx.gbl...

Hi,
Is it good practice using GOTO in .NET application?

Please advice.

Thanks, Kartic

[Jay B. Harlow [MVP - Outlook]]

Cor,
First a question: Why are you attempting to build a long thread? ;-)
As I told Robin:

Remember bad use of a Goto does not make the Goto bad!

Too many developers think Goto is Bad! as they have seen bad uses of Goto
too often...

The second link is interesting, I don't see what you are trying to say with
the first (other then who wrote the second).

Just a thought
Jay

"Cor Ligthert" <no**********@p lanet.nl> wrote in message
news:e%******** ********@TK2MSF TNGP11.phx.gbl. ..

Hi Jay B. (And Bill)

I never come with documents, however this greath Dutchman will turn around
about your writting.

(He has done very much for modern programming, in my idea most modern
languages derives partialy from his ideas)

http://www.cs.utexas.edu/users/EWD/

http://www.acm.org/classics/oct95/

Cor

[Robin Tucker]

I think though, if I remember my formal specification classes, that using
GOTOs does tend to mess up any mathematical description of your process (not
that we tend to design our applications in "Z" before implementing them in
VB!).

"Jay B. Harlow [MVP - Outlook]" <Ja************ @msn.com> wrote in message
news:%2******** *******@TK2MSFT NGP11.phx.gbl.. .

Cor,
First a question: Why are you attempting to build a long thread? ;-)
As I told Robin:

Remember bad use of a Goto does not make the Goto bad!

Too many developers think Goto is Bad! as they have seen bad uses of Goto
too often...

The second link is interesting, I don't see what you are trying to say with the first (other then who wrote the second).

Just a thought
Jay

"Cor Ligthert" <no**********@p lanet.nl> wrote in message
news:e%******** ********@TK2MSF TNGP11.phx.gbl. ..

Hi Jay B. (And Bill)

I never come with documents, however this greath Dutchman will turn around about your writting.

(He has done very much for modern programming, in my idea most modern
languages derives partialy from his ideas)

http://www.cs.utexas.edu/users/EWD/

http://www.acm.org/classics/oct95/

Cor