The MouseEvent.getModifierState() method returns the current state of the specified modifier key: true if the modifier is active (i.e., the modifier key is pressed or locked), otherwise, false.
See KeyboardEvent.getModifierState() for details.
getModifierState(key)keyA modifier key value. The value must be one of the KeyboardEvent.key values which represent modifier keys or "Accel" . This is case-sensitive.
A boolean value.
MouseEvent this method belongs to.KeyboardEvent.getModifierState