QT: cannot access private member declared in class 'QByteArray'

Question

I've been trying to create a random phrase generator, which reads nouns from one text file and verbs from another text file. That all worked, but now I'm trying to write a method that capitalizes the first letter of the subject, but keep getting the errors

error: C2248: 'QByteArray::operator QNoImplicitBoolCast' : cannot access private member declared in class 'QByteArray'

see declaration of 'QByteArray::operator QNoImplicitBoolCast'

see declaration of 'QByteArray'

I'll post the code for the method (sorry if its not in proper format I'm new)

    void MainWindow::returnCap(QString sub){

        char *str;
        QByteArray ba;
        ba = sub.toLatin1();
        str = ba.data();
        QString firstLetter;
        firstLetter = str[0];
        QString cappedFirstLetter;
        cappedFirstLetter = firstLetter.toUpper();
        char flc; //firstLetterChar
        flc = cappedFirstLetter.toLatin1();
        str[0] = flc;
    }

Thanks for any help!

toLatin1 returns QByteArray... you have to cast it to char* with .data or char — Matthias, Jul 02 '14 at 14:31
If you're trying to make the fist letter of `sub` upper-case, why not simply do `sub[0] = toupper(sub[0])`? Also, you're passing `sub` *by value* so you're only modifying a copy. — Some programmer dude, Jul 02 '14 at 14:33

vahancho · Accepted Answer · 2014-07-02T14:43:46.537

1

The problem is that you assigning a byte array to a single character. However you need only one character from the byte array:

char flc; //firstLetterChar
flc = cappedFirstLetter.toLatin1()[0];

UPDATE:

I would solve your problem in the following way:

QChar c1 = sub[0];
c1 = c1.toUpper();
sub.replace(0, 1, c1);

edited Jul 02 '14 at 14:43

answered Jul 02 '14 at 14:33

vahancho

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score 0 · Answer 2 · answered Jul 02 '14 at 14:31

0

You call the member function toLatin1, which returns a QByteArray. You then assign this QByteArray object to a char variable (not char*, just char).

answered Jul 02 '14 at 14:31

Some programmer dude

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QT: cannot access private member declared in class 'QByteArray'

2 Answers2