Where Is IntelliSense For "goto" statements?

[Theraot]

That was a good point, and that's why we use pokémon error handling: to put a limit to that who knows where. The gotta catch'all approach is good when calling third party code in particular when it has the potential to be wrote letter by who knows who. By the way, I browsed my more relevant solution for an use of goto, and found only one, and I'm proud of it:

    \[DebuggerNonUserCode()\]
    private static int Sqrt(int number)
    {
        //Newton's method aproximation for positive integers
        //if (n == 0) return 0;
        int x, \_x = number >> 1;
    back:
        x = (\_x + number / \_x) >> 1;
        if (x <= \_x) return \_x;
        \_x = x;
        goto back;
    }

I did my best at that time to increase performance of that code without going to a non-portable solution. I wonder if anybody will find a better way to write it.

[Antzzz]

Dave Kreskowiak wrote:

>SMACK!!< You what? I haven't found a need for a GOTO in the last, oh, 15 years...

You've obviously never coded in C for a low power micro with no exception handling... GOTO has it uses - mostly for bailing out to a common exit point when something goes pearshaped and you need to clean up after yourself. Only other option in these circumstances is horribly nested if statements - using a GOTO results in much cleaner/readable code. A TRY/CATCH block would do the trick nicely, but most low power (I'm not talking ARMs here, old crusty Renesas M16s and the like) micros used in industry don't have exception handling.

[Sergelp]

Ever heard of try/catch - if then else ... Goto usage is the ultimate spaghetti type programming, so you don't want to go that way. It's not a crusade, it's a fact. Believe me - a former spaghetti analyser that has programmed for years in language like Data General/UBB (Universal Business BASIC). For a long time in those languages (interpreter based) the "do while/for loop" instruction didn't exist and every line in your program had a linenumber. With the goto you could force a kind of do while or even if then else. Also a goto made the program go faster (interpreter) skipping the lines that it didn't needed. The goto was of course abused making the readability very poor. Here's an example of a do while in old BASIC 100 if i<10 then 110 ... (instruction) 120 ... 130 ... 140 goto 100 150 end if Gradually the linenumber became labels and vb3,vb4,... took on this way of programming. @start 100 if i<10 then 110 ... 120 goto @start 130 end if Those (nostalgic) days are gone now... :-) I think the only reason why MS didn't completely erase the command is backwards compatibility with VB6 where you had to use it with (on) error handling. Now you have an (even better) initiative for this, the try/catch/finaly block. The finaly part is certainly an improvement. Conclusion : "Spaghetti is nice as long as it's on your plate accompagnied with some tomatoesauce, cheese and some tabasco".

modified on Tuesday, July 13, 2010 5:20 AM

[Bujar Tahiri]

Richard Blythe wrote:

I don't use the: "goto" statement very often but I have started using it more frequently. Does anyone know why Visual Studio does not implement IntelliSense for goto statements?

Try it in VB, maybe C# does not have it

[Richard Blythe]

My primary reason is for complex validation that share the same exception. Here's an example:

public void validateSomething(someComplexType)
{
if (first_conditionFails)
goto Label_Error;
else if (complexAlgorithmRequired)
{
//init vars for algorithm...
if (first_conditionFails)
goto Label_Error;
else if (second_conditionFails)
goto Label_Error;
else //perform second phase of algorithm
{
//init vars for second phase...
if (first_conditionFails)
goto Label_Error;
else if (second_conditionFails)
goto Label_Error;
}
}
//skip the end-of-routine error code
return;

Label_Error:
//set class vars...
//to an invalid state...
//...
throw new someException();
}

How would you implement this with try/catch without a whole bunch of "throw someException()"?

The mind is like a parachute. It doesn’t work unless it’s open.

[engchin]

You can put the codes under Label_Error in a separate function, say CatchError(). Then, replace every line of your goto label_error statement with a statement calling the CatchError function. This would be much more readable and at the same time avoid all the pitfalls of goto.

[Sergelp]

Hi Richard, I didn't know for for what purpose you were trying to use the goto that's why I assumed it was for as try catch system (is the most common use). On your case it's not the try/catch that has to be used. How I would solve this problem, is by using validationfunction with a return value. This way you could even put your validation in a separate class or library. It's a standalone function. Best practice to seperate this because if your using winforms, you could easily use the same validation when you decide to use ASP.net or something else. Compile the lib as a dll, put the function public and you can use it in any language. The enum is practical in .net because the intellisense kicks in but you could easily test it on the values 1,2,3 In fact you could consider the return value as a kind of a label. I'll put it in VB because I know this best but you'll get the idea. Enum ValidateError firstcondition = 1 secondcondition = 2 thirdcondition = 3 End Enum Private Sub ValidateMessage(ByVal someComplexType) Select Case ValidateSomething(someComplexType) Case ValidateError.firstcondition MsgBox("first") Case ValidateError.secondcondition MsgBox("second") Case ValidateError.thirdcondition MsgBox("third") Case Else MsgBox("ok") End Select End Sub Private Function ValidateSomething(ByVal someComplexType) As ValidateError If someComplexType < 0 Then Return ValidateError.firstcondition End If If someComplexType > 100 Then Return ValidateError.secondcondition End If If someComplexType > 1000 Then If someComplexType > 2000 Then Return ValidateError.thirdcondition End If End If '... End Function What do you think of it ? Regards Serge

[Dave Kreskowiak]

Antzzz wrote:

You've obviously never coded in C for a low power micro with no exception handling...

Actually, I have, a very long time ago. Since you mentioned Visual Studio, you're not writing code for a micro, but for some flavor of Windows. I'm assuming you're using a managed language and not C++, which, frankly, Intellisense always has, and still does to this day, suck at.

A guide to posting questions on CodeProject[^]
Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
     2006, 2007, 2008
But no longer in 2009...

[Antzzz]

We write C for a variety of micros, using VS (VC) as the IDE and an integrated compiler to build the binary for the platform... Not all VS projects end up on Windows!

[YSLGuru]

Richard, Yo've gotten a lot of negative replies (that I can see) because the GOTO statement is considered to be in the top 10 of BAD CODING PRACTICES in OOP. This i because GOT equates to 'Spaghetti Code' and thats something none of us ever want to hae to deal with. If you are coding properly you don;t need to use GOTO in an OOP langauge; assuming you are using an update or current version. If you were using say VB 3 or something that may be a differnet story.