Node.js - events module

// Here we require in the 'events' module and save a reference to it in an events variable
let events = require('events');

// function which expects 'data' to be passed and will log a string to the console which incorporates that data
let listenerCallback = (data) => {
    console.log('Celebrate ' + data);
}

// Create an instance of the EventEmitter class
let myEmitter = new events.EventEmitter();

// .on() method takes the name of the event (as a string) as its first argument & the listener callback function as its second argument
myEmitter.on('celebration', listenerCallback);

// .emit() method which announces a named event has occurred. Takes name of the event as its first argument & a string of your choice as the second argument
myEmitter.emit('celebration', 'good times, come on! Here we go!');

// Run program by typing node app.js onto the terminal