EventEmitter.on() method

Bind an event listener to fire when an event occurs.

Signature:

class EventEmitter {
  on(event: EventType, handler: Handler): EventEmitter;
}

Parameters

Parameter	Type	Description
event	EventType	the event type you'd like to listen to. Can be a string or symbol.
handler	Handler	the function to be called when the event occurs.

Returns:

EventEmitter

this to enable you to chain method calls.