Display QString

Question

I'm totaly new in QT programming so i got a bit noob question. Why I get this error?

undefined reference to `Messenger::newParticipant(QString)'

main.cpp

#include <QCoreApplication>
#include <QTextStream>
#include "messenger.h"
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    Messenger* messenger = new Messenger();
    messenger->newParticipant("AAAA");
    QTextStream qout(stdout);
    qout << "asd\n";
    qout.flush();
    return a.exec();
}

messenger.h

#ifndef MESSENGER_H
#define MESSENGER_H

#include "network/client.h"
#include <iostream>
#include <QTextStream>
class Messenger
{
public:
    Messenger();
   void newParticipant(const QString &nick);
private slots:
    void sendMessage(const QString &message);
    void participantLeft(const QString &nick);


};


#endif // MESSENGER_H

messenger.cpp

#include "messenger.h"

Messenger::Messenger()
{
        QTextStream qout(stdout);
        qout << "a. Constructor...\n";
        qout.flush();
}
void newParticipant(const QString &nick)
{
    if (nick.isEmpty())
        return;

    QTextStream qout(stdout);
    qout << nick;
    qout.flush();
}

Answer 1

You forgot to specify classname in definition of newParticipant.

Try to change it to void Messenger::newParticipant(const QString &nick) in messenger.cpp.

Answer 2

That's because you forgot to write Messenger:: before newParticipant definition in your cpp file.