start socket.io server code example

Example 1: socket io script

<script src="/socket.io/socket.io.js"></script>
<script>
  const socket = io();
</script>

Example 2: create a web server node js w socket.io

var app = require('express')();
var http = require('http').createServer(app);
var io = require('socket.io')(http);

app.get('/', (req, res) => {
  // Ran when a GET request to path '/'
  res.sendFile(__dirname + '/index.html');
});

io.on('connection', (socket) => {
  // Ran when a socket connected
});

http.listen(3000, () => {
  // Ran when server is ready to take requestes
});