How to send a QString to debug output?

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());

you should use it a little different way: `qDebug() << letters;` — mexus, Jan 20 '14 at 11:39

score 13 · Accepted Answer · answered Jan 20 '14 at 11:41

13

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.

answered Jan 20 '14 at 11:41

SirDarius

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That is what I have done and it doesn't work – user929404 Jan 20 '14 at 11:44
2

@user929404 it is `qDebug` and not `QDebug`. Read. Don't guess. – RedX Jan 20 '14 at 11:45
2

worth to mention that you can print QString with qDebug("%s", qPrintable(qstring_instance)); – Kamil Klimek Jan 21 '14 at 07:25

How to send a QString to debug output?

1 Answers1