addEventListener

function

function addEventListener<K extends keyof WindowEventMap>(type: K, listener: (this: Window, ev: WindowEventMap[K]) => any, options?: boolean | AddEventListenerOptions): void

Registers an event listener in the global scope, which will be called synchronously whenever the event type is dispatched.

addEventListener('unload', () => { console.log('All finished!'); });
...
dispatchEvent(new Event('unload'));

function

function addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void

Registers an event listener for an arbitrary event type on the global scope.