EventEmitter is a Node native class containing a set of methods to operate on the events.
#node#module#events
constEventEmitter=require('events');constemitter=newEventEmitter();// Set an event listeneremitter.on('userSubscribed',function(eventArg){console.log("User subscribed at ",eventArg.date);// Do something when user subscribes});// Raise an event and pass data as the second argumentemitter.emit('userSubscribed',{date:Date.now()})