Scripter Javascript Tutorial

33 instanceof comparison

MDN: Operators: instanceof

The instanceof comparison returns true if an object is an instance of a particular object type.

function HandleMIDI(event) {
	if ( event instanceof NoteOn ) {
		Trace("NoteOn");
	}
}

In the above example:

• Line 1: A MIDI event is passed into the HandleMIDI() function.

• Line 2: The instanceof comparison is used to determine whether or not the event is NoteOn.

• Line 3: If the event is a NoteOn, then the script does something with that event. Otherwise, the event is ignored.