C++ easy question Classes

[arturs]

I have a MainWindow class and in the class I defined in public part QString app_language

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    QString app_language;

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    QString app_language;

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I would like to access to QString app_language; from another Class

I tried to use the following code:
MainWindow.app_language;

but It does not work

How to do it ?

Regards
Artur

[Zlatomir]

You can't access a non-static member like that, you need an instance of the MainWindow class (or a reference or a pointer to an instance).
For example in main you'll access it like this:

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow instanceOfMainWindowClass;
 
    instanceOfMainWindowClass.app_language = "romanian";    
 
    instanceOfMainWindowClass.show();
 
    return a.exec();
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow instanceOfMainWindowClass;

    instanceOfMainWindowClass.app_language = "romanian";    

    instanceOfMainWindowClass.show();

    return a.exec();
}

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In another class you'll need to pass a pointer or reference to the instance of MainWindow to the constructor (or create a method to set the pointer) of your second class (constructor approach is similar to how you pass the parent pointer with Qt), i'll let you try that for an exercise

And i really recommend you read a C++ book (like Thinking in C++ - it can be found for free in electronic format) or else Qt will seem very hard or read Introduction to design patterns in C++ with Qt (it's available for free from ICS, you'll need to register on their site: http://www.ics.com/design-patterns ) this one starts with C++ and introduces Qt right after.