Advanced Node.js Development

The io.on method

In order to play around with this inside Atom, in server.js, we are going to call a method on io called io.on:

app.use(express.static(publicPath));io.on();

The io.on method lets you register an event listener. We can listen for a specific event and do something when that event happens. One built-in event that we're going to use—the most popular one—is called connection. This lets you listen for a new connection of a client to the server, and lets you do something when that connection comes in. In order to do something, you provide a callback function as the second argument, and this callback function is going to get called with a socket:

io.on('connection', (socket) => {});

This socket argument is really similar to the