const express = require('express'); const app = express(); const http = require('http'); const server = http.createServer(app); const { Server } = require("socket.io"); const io = new Server(server); const connectUsers = [] io.on('connection', (socket) => { console.log(socket.id) socket.on('joinRoom', ({username}) => { connectUsers.push(username) socket.emit('roomJoined', connectUsers) }); }); server.listen(3000, () => { console.log('listening on *:3000'); });