how socket.io works code example

Example 1: socket..io

<script src="https://cdn.socket.io/socket.io-3.0.1.min.js"></script>

Example 2: socket.io documentation

const socket = new WebSocket('ws://localhost:3000');socket.onopen(() => {  socket.send('Hello!');});socket.onmessage(data => {  console.log(data);});