QString Split() issue.

[JonB]

@Uberlinc

tmp = line.split(",");
qDebug() << line << tmp.length()  << tmp;

[jsulm]

@Uberlinc said in QString Split() issue.:

Can you see the flaw in the top piece of code?

No.
You did not tell what EXACT input string you're splitting?
Why don't you check that? It probably does not contain any ','

[Uberlinc]

@jsulm

Here is the file that I'm reading in from at its entirety:

20210101,23,27,44,1,41,18
20210107,20,44,20,31,13,34
20210114,23,24,36,28,5,8
20210121,23,33,44,8,38,22
20210128,18,6,16,30,17,34
20210204,29,8,20,3,4,12
20210211,11,28,37,38,5,9
20210218,34,4,32,25,40,3
20210225,26,34,25,31,38,5
20210304,31,3,41,28,12,2
20210311,37,39,41,28,26,19
20210318,2,11,38,43,38,23
20210325,45,7,8,37,14,12

[Uberlinc]

@JonB said in QString Split() issue.:

@Uberlinc

tmp = line.split(",");
qDebug() << line << tmp.length()  << tmp;

22:05:08: Starting /home/linc/Documents/Workspace/Qt/build-SimpleFile-Desktop-Debug/SimpleFile...
"20210107,20,44,20,31,13,34" 7 ("20210107", "20", "44", "20", "31", "13", "34")
"20210114,23,24,36,28,5,8" 7 ("20210114", "23", "24", "36", "28", "5", "8")
"20210121,23,33,44,8,38,22" 7 ("20210121", "23", "33", "44", "8", "38", "22")
"20210128,18,6,16,30,17,34" 7 ("20210128", "18", "6", "16", "30", "17", "34")
"20210204,29,8,20,3,4,12" 7 ("20210204", "29", "8", "20", "3", "4", "12")
"20210211,11,28,37,38,5,9" 7 ("20210211", "11", "28", "37", "38", "5", "9")
"20210218,34,4,32,25,40,3" 7 ("20210218", "34", "4", "32", "25", "40", "3")
"20210225,26,34,25,31,38,5" 7 ("20210225", "26", "34", "25", "31", "38", "5")
"20210304,31,3,41,28,12,2" 7 ("20210304", "31", "3", "41", "28", "12", "2")
"20210311,37,39,41,28,26,19" 7 ("20210311", "37", "39", "41", "28", "26", "19")
"20210318,2,11,38,43,38,23" 7 ("20210318", "2", "11", "38", "43", "38", "23")
"20210325,45,7,8,37,14,12" 7 ("20210325", "45", "7", "8", "37", "14", "12")
"" 1 ("")
ASSERT failure in QList<T>::operator[]: "index out of range", file /usr/include/x86_64-linux-gnu/qt5/QtCore/qlist.h, line 552

[JonB]

@Uberlinc So? How many elements in the list does the output show when it ASSERTS?

[J.Hilk]

@Uberlinc said in QString Split() issue.:

"" 1 ("")

looks like you have an empty line in your file.
I would suggest simply skipping, if your don't get the required amount of entries after the split

strTmp = linest.split(",");

if(strTmp.size() < 7){
    qDebug() << "Invalid linest:" << linest;
    return;
}

[Uberlinc]

@J-Hilk said in QString Split() issue.:

looks like you have an empty line in your file.
I would suggest simply skipping, if your don't get the required amount of entries after the split

I did see that, and so I checked the file.
Yes, there was a blank line at the end of the file.
So, I removed it.
Definitely not there now.

The same error occurred.

Weird?

Here is the code to read the file.
Could the error be here instead?

void MainWindow::readInfile(QString filename)
{
    QFile file(filename);
    if(!file.open(QFile::ReadOnly |
                  QFile::Text))
    {
        QMessageBox::about(this, "Error", "Could not open file for reading");
        return;
    }

    QTextStream stream(&file);
    QString line = stream.readLine();
    while (!line.isNull())
    {
        // process information
        line = stream.readLine();
        loadVec(line);
    }


    QMessageBox::about(this, "Done", "File contents read in!");
    file.close();
}

[jsulm]

@Uberlinc said in QString Split() issue.:

Could the error be here instead?

Please first check the string you're splitting!
This is first thing to do in such a situation...
You also should ALWAYS check the indexes when handling data! Not just think it will be exactly what you expect.

[goloviznin.k]

Hey, maybe this will help you somehow:

tmp = line.split(",", QString::SkipEmptyParts);
		for (int i = 0; i < tmp.count(); ++i) 
		{
			arrstuff[i] = tmp[i].toInt();
			std::cout << arrstuff[i] << " ";
		}

[Uberlinc]

@jsulm said in QString Split() issue.:

Please first check the string you're splitting!
This is first thing to do in such a situation...

I did.
Please see the qDebug output above.
It definitely contains commas.
I have removed any and all spaces/carriage returns at the end of the file.
From what I can see, the lines are indeed being read in as per QDebug output above.

Thanks.

[J.Hilk]

@Uberlinc line.isNull() != line.isEmpty()

also you're reading the line twice and not checking against empty with the 2nd read...

QTextStream stream(&file);
    while (!stream.atEnd())
    {
        // process information
        QString line = stream.readLine();
        if(!line.isEmpty())
           loadVec(line);
    }

[jsulm]

@Uberlinc said in QString Split() issue.:

Please see the qDebug output above

Where?
You posted new code but no new debug output as far as I can see.
Please post the string you're trying to split. You expect it to have at least 5 commas, right?
Does the string in question contain 5 commas?

[Uberlinc]

I think I've sorted it now.
It was an error in the file read loop.

Thank you for your assistance.