qt doubt!!

[harivittal.hk]

hi! m new to qt programin..m nt understandin this piece of code..plz help.
here is the code:
"
namespace Ui
{
class MainWindowClass;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

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

private:
Ui::MainWindowClass *ui;
};
"
my doubt is why a class is defined in namespace,is tat allowed..is the word "namespace" a return type or acting as a datatype.
any help is appreciated..:(

[smartbei]

Firstly, please use the [code ] tags - just stick your code between [code ] and [/code ] (without the spaces of course), so that it will look better and stay formatted. (Edit your post)

About your question - I think you should take a look at http://www.cplusplus.com/doc/tutorial/namespaces/ for example - it explains in relative detail what namespaces are and how to use them.