How to send a QString to debug output? [duplicate]

Question

I cannot print out a QString in Qt using QDebug.

Below are some attempts (none work):

    QDebug(letters.toStdString());
    QDebug(letters.toLatin1());
    QDebug() << letters.toUtf8();
    QDebug() << letters.toWCharArray();
    QDebug() << letters.toStdString();
    QDebug() << letters;

I have included:

#include <QtDebug>
#include <QDebug>

I am using Qt 5.2. I also added CONFIG += console to my project file

My error is "no matching function for call to QDebug::QDebug()"

I also got "QDebug(QByteArray) is ambiguous" for QDebug(letters.toLatin1());

Maund

What error do you get ? – Fastening

you should use it a little different way: qDebug() << letters; – Poler

@Fastening I edited the question to answer you. – Maund

@Poler Look at the sixth attempt – Maund

QDebug and qDebug are not the same... – Fastening

@Maund Look at the lower-case letter q in my comment – Poler

That was pretty dumb of me. Sorry guys – Maund

Answer 1

The correct way to do so is:

#include <QDebug>

// snip...

QString letters;

qDebug() << letters;

Be careful to use qDebug() beginning with a small letter, since it is not the same thing as the QDebug class.

See http://qt-project.org/doc/qt-5.0/qtcore/qtglobal.html#qDebug. It is a convenience function that returns an already configured QDebug object.

Fastening

That is what I have done and it doesn't work – Maund

@Maund it is qDebug and not QDebug. Read. Don't guess. – Bagpipes

worth to mention that you can print QString with qDebug("%s", qPrintable(qstring_instance)); – Alternative