socket io websocket code example

Example 1: socket io script

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

Example 2: js socket.emit

const socket = io('ws://localhost:3000');
socket.on('connect', () => {  
  // either with send()  
  socket.send('Hello!');
  // or with emit() and custom event names  
  socket.emit('salutations', 'Hello!', { 'mr': 'john' }, Uint8Array.from([1, 2, 3, 4]));});
// handle the event sent with socket.send()
socket.on('message', data => {
  console.log(data);
});
// handle the event sent with socket.emit()
socket.on('greetings', (elem1, elem2, elem3) => {
  console.log(elem1, elem2, elem3);
});

Example 3: socketio connect websockets

var ws = new WebSocket('ws://localhost/socket.io/?EIO=3&transport=websocket');
ws.send('42' + JSON.stringify(['hello', 'there']));
// ws.onmessage will get a MessageEvent object with the data property being encoded in the similar way.

Example 4: socketio connect websockets

var socket = io('http://localhost');
socket.emit('hello', 'there');