EventEmitter.on() method

Bind an event listener to fire when an event occurs.

Signature:

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 calls.