Diaries of Learning Qt (1.2) Modularity

In this example program, we can see scraps like this:
    MainWindow::MainWindow()
    {
        textEdit = new QPlainTextEdit;
        setCentralWidget(textEdit);

        createActions();
        createMenus();
        createToolBars();
        createStatusBar();
    ......
But when I do it myself, usually I put all the codes together, like this:

    MainWindow::MainWindow()
    {
        textEdit = new QPlainTextEdit;
        setCentralWidget(textEdit);
   
        filemenu = new QMenu("&File");
        menuBar()->addMenu(filemenu);

            newaction = new QAction(QIcon(":/images/new.png"),tr("&New"),this);
            newaction->setShortcut(QKeySequence::New);
            newaction->setStatusTip(tr("Build a new file"));
            connect(newaction,SIGNAL(triggered()),this,SLOT(newfile()));
            filemenu->addAction(newaction);
    ......

The difference is just what we call "Modularity".
It's importance and benefit are so clear that there's no need to say more.
Briefly, you should put relevent codes together as a function or class.