how to delete a widget

ACtually im having 2 Qwidgets say "Widget" , "NewWidget". im calling "NewWidget" in "Widget" keypress event and viced versa,

void Widget::keyPressEvent(QKeyEvent *qv)
{
// i want to delete "Widget" here before i call "NewWidget"
NewWidget *newWidget = new NewWidget();
newWidget->setStyleSheet("background-color:black;");
newWidget->setGeometry(0,0,640,480);
newWidget->show();
}

I want to delete or destroy the "Widget" before calling "NewWidget"

Your trying to delete this object in its own function which is dangerous(object self destruction).

May be you can use this->deleteLater(); in this case.

But destroying self object is bad idea.

What is your requirement.?

im running this executable in ARM based board which is having very less memory.Actually im using 4 widgets in my application,so if i delete the widget while calling another , i can save the memory thats the reason im looking for.

As prasad_N said, use deleteLater() if you do it inside the widget.
If you need to delete the current widget before you create the new one, then you need to emit a signal, connect it to some slot using a Qt::QueuedConnection and in the slot first delete the current widget, then create the new one.

Cheers,
_