KeyboardEvent

The KeyboardEvent.altKey read-only property is a boolean value that indicates if the alt key (Option or ⌥ on macOS) was pressed (true) or not (false) when the event occurred.

The KeyboardEvent.code property represents a physical key on the keyboard (as opposed to the character generated by pressing the key).

The KeyboardEvent.ctrlKey read-only property returns a boolean value that indicates if the control key was pressed (true) or not (false) when the event occurred.

The UIEvent.detail read-only property, when non-zero, provides the current (or next, depending on the event) click count.

The KeyboardEvent.isComposing read-only property returns a boolean value indicating if the event is fired within a composition session, i.e., after Element/compositionstart_event and before Element/compositionend_event.

The KeyboardEvent interface's key read-only property returns the value of the key pressed by the user, taking into consideration the state of modifier keys such as Shift as well as the keyboard locale and layout.

The KeyboardEvent.location read-only property returns an unsigned long representing the location of the key on the keyboard or other input device.

The KeyboardEvent.metaKey read-only property returning a boolean value that indicates if the Meta key was pressed (true) or not (false) when the event occurred.

The repeat read-only property of the true if the given key is being held down such that it is automatically repeating.

The KeyboardEvent.shiftKey read-only property is a boolean value that indicates if the shift key was pressed (true) or not (false) when the event occurred.

The UIEvent.view read-only property returns the is the Window object the event happened in.

The KeyboardEvent.getModifierState() method returns the current state of the specified modifier key: true if the modifier is active (that is the modifier key is pressed or locked), otherwise, false.