1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18const express = require('express'); const app = express(); const server = require('http').createServer(app); const io = require('socket.io')(server); const port = process.env.PORT || 3000; app.use(express.static(__dirname + '/public')); io.on('connect', onConnect); server.listen(port, () => console.log('server listening on port ' + port)); function onConnect(socket){ console.log('connect ' + socket.id); socket.on('disconnect', () => console.log('disconnect ' + socket.id)); }