goto... Who uses it?

dusty_dex

Not without being forced to. Futzing around with an old 8-bit BASIC - ATARI. It was a shockingly poor implementation of the language. Otherwise I can't recall using goto in any C-like language at all. ever!

Q. Hey man! have you sorted out the finite soup machine? A. Why yes, it's celery or tomato.

BobJanova

I don't use it in high level languages where there is a structured alternative. The only time I'm tempted is the 'double break', i.e. wanting to escape from two levels of nested looping; to do this you have to create a method to do the double loop and use return, which often feels like overkill.

Dalek Dave

I have used it for some lazy error handling.

--------------------------------- I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^]

DanielSheets

    public static void SaveChartData(List dataList)
    {
        int totalDelays = 0;
        int value = 0;
        string errorString = "";
        // Use a temporary file in case there are any parse errors.
        string tmpFilePath = applicationPath + "TmpChartData.csv";
        using (StreamWriter sw = new StreamWriter(tmpFilePath))
        {
            foreach (DataGridClass dgc in dataList)
            {
                if (!int.TryParse((dgc.MATL.Equals("") ? "0" : dgc.MATL), out value))
                {
                    errorString = dgc.MATL;
                    goto ParseError;
                }
                totalDelays += value;
                if (!int.TryParse((dgc.EQUIP.Equals("") ? "0" : dgc.EQUIP), out value))
                {
                    errorString = dgc.EQUIP;
                    goto ParseError;
                }
                totalDelays += value;
                if (!int.TryParse((dgc.People.Equals("") ? "0" : dgc.People), out value))
                {
                    errorString = dgc.People;
                    goto ParseError;
                }
                totalDelays += value;
                if (!int.TryParse((dgc.Defects.Equals("") ? "0" : dgc.Defects), out value))
                {
                    errorString = dgc.Defects;
                    goto ParseError;
                }
                totalDelays += value;
                if (!int.TryParse((dgc.Other.Equals("") ? "0" : dgc.Other), out value))
                {
                    errorString = dgc.Other;
                    goto ParseError;
                }
                totalDelays += value;
                sw.WriteLine("{0},{1},{2},{3},{4},{5},{6},{7},{8},{9},{10}",
                    dgc.Year, dgc.Month, dgc.Goal, dgc.Completions, totalDelays, dgc.to,
                    dgc.MATL, dgc.EQUIP, dgc.People, dgc.Defects, dgc.Other);

                totalDelays = 0;
                value = 0;
            }
        }
        // If we got this far then there were no parse errors.
        File.Copy(tmpFilePath, chartData, true);
        return;
    ParseError:
        string msg = string.Format("Unable to parse data. Verify its entered correctly.\\r\\nValue = {0}", errorString);
        MessageBox.Sho

Mauro Leggieri

Eddy Vluggen wrote:

Do you have an example? After years in the trade, I have still to see the first instance where it actually improves readability/maintainability.

Hi, In C/C++ for e.g. in a switch statement where you must share some portion of code. Although one can put that shared part inside another function, for visibility & tracking purposes, some times is better to have the code in the same screen avoiding scrolling up and down to follow the code. Believe it, is real but I cannot show company code. I don't remember which old Pascal guru told that but sometimes a goto is preferable instead of doing a lot of work to avoid its usage and make the code difficult to read. For the other side, as an assembly programmer... I see JMPs everywhere hehehe. Regards, Mauro.

Lost User

Read up on exception-handling.

Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^]

DanielSheets

Its all relative I suppose.

Lost User

Mauro Leggieri wrote:

For the other side, as an assembly programmer... I see JMPs everywhere hehehe.

..simply because there's little alternative in assembly. Assumed we weren't talking about assembly, but higher-level languages - there are few people still working professionally with assembly.

Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^]

DanielSheets

For what part? Why would I need to use exception handling when thats exactly what TryParse is used for (assuming thats what you're talking about)?

wizardzz

Use it in .bat files all the time.

lewax00

I've using one while I test some timeout code on a function, but I'll refactor it out before I commit it. Just nice to see the whole process at once for now (and I can make sure it works before I spend time figuring out exactly how to best cleanup before cancelling it).

BobJanova

That's horrible. Repeated code, and mixing of data management and UI code. It's crying out for throwing exceptions which you catch in the UI code, and a method

int parseNumericValue(String text){
int result;
if(!int.TryParse(text == "" ? "0" : text, out result))
throw new DataFormatException("Unable to parse data. Verify its entered correctly.\r\nValue = "+text);
return result;
}

(and that's if the default exception from Parse doesn't do the job which it probably does). This is translated VB. And that's not a good thing.

GuyThiebaut

That's a pattern I have come across in Oracle PL/SQL and it does the job well. Of course one can use an if, as you mention, but if it is used judiciously it works well and does not break the logic any more than an else does.

“That which can be asserted without evidence, can be dismissed without evidence.”

― Christopher Hitchens

Lost User

..on how to throw an exception. I wouldn't even expect the "if's", but rather a loop; and have each condition in a separate class.

        using (StreamWriter sw = new StreamWriter(tmpFilePath))
        {
            foreach (DataGridClass dgc in dataList)
            {
                foreach (var thingToTest in ParsesClasses)
                {
                     Results.Add( thingToTest (dgc) );
                }

Wrap it in a try-catch, and done.

Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^]

DanielSheets

Thats swift. I'll be the first to admit that I dont have the experience or knowledge of 90% of the people here. Interesting.

Dave Kreskowiak

I haven't used a "goto" since.....let's see now.....1995, in some assembly language I was writing for a graphics library. This s, if you call any flavor of JMP a "goto". Come to think of it, that's probably around the last time I've ever used the keyword "goto" in any higher languages.

A guide to posting questions on CodeProject[^]
Dave Kreskowiak

Dexterus

For this same reason it was used in our C code (kernel, various drivers). Not had to use it yet but I can see some uses if you want the CPU/compiler to execute/optimize properly.

dusty_dex

That looks bad to me. Aren't you supposed to use

break ;

to jump out of loops? Exception handling will usually bog down the handled block of code.

Q. Hey man! have you sorted out the finite soup machine? A. Why yes, it's celery or tomato.

Chris Losinger

depends on the language. sometimes, there is no way to avoid it.

image processing toolkits | batch image processing

glennPattonWork3

I have always thought goto was the equlivant of the assembly language jmp (blocking?), if it is I used one this morning. Goto is also acceptable in RTOS situations (which Windows isn't) if you want the valve to close now and not later. Glenn