qt - Why is QString printed with quotation marks?

Question

So when you use qDebug() to print a QString, quotation marks appears suddenly in the output.

int main()
{
    QString str = "hello world"; //Classic
    qDebug() << str; //Output: "hello world"
    //Expected Ouput: hello world
}

I know we can solve this with qPrintable(const QString), but I was just wondering why does QString work like that?, and Is there a method inside QString to change the way it's printed?

Answer 1

Qt 5.4 has a new feature that lets you disable this. To quote the documentation:

QDebug & QDebug::?noquote()

Disables automatic insertion of quotation characters around QChar, QString and QByteArray contents and returns a reference to the stream.

This function was introduced in Qt 5.4.

See also quote() and maybeQuote().

(Emphasis mine.)

Here's an example of how you'd use this feature:

QDebug debug = qDebug();
debug << QString("This string is quoted") << endl;
debug.noquote();
debug << QString("This string is not") << endl;

Another option is to use QTextStream with stdout. There's an example of this in the documentation:

QTextStream out(stdout);
out << "Qt rocks!" << endl;