var app = require('express')(); var http = require('http').Server(app); var io = require('socket.io')(http); const port = 3000; //Whenever someone connects this gets executed io.on('connection', function(socket) { console.log('A user connected'); //Whenever someone disconnects this piece of code executed socket.on('disconnect', function () { console.log('A user disconnected'); }); }); http.listen(port, function() { console.log('listening on *:3000'); });