Send value or string from main.cpp to mainwindow.cpp (Qt Creator) : I'm a newbie in this world, but i need a help to send a value from main.cpp to mainwindow.cpp before opening the window.

More or less, the process should be this:

    #include "mainwindow.h"
    #include <QApplication>
    
    int main(int argc, char *argv[])
    {
        QApplication a(argc, argv);
        MainWindow w;
    
        // some code here where I control parameters
    
        // Here I have some values and/or strings to send to MainWindow
    
        w.show();
        return a.exec();
    }

Now how can I send them? I don't want to create a file where put these values.

Thanks in advance for the help