UIEvent()constructor creates a new
MouseEvent.buttonsread-only property indicates which buttons are pressed on the mouse when the event is triggered.
UIEvent.isCharread-only property returns a
Booleanindicating whether the event produced a key character or not.
UIEvent.viewread-only property returns the
WindowProxyobject from which the event was generated. In browsers, this is the
Windowobject the event happened in.