How to close Node Express server?

To close Node Express server, we call close on the server instance.

For instance, we write

const server = app.listen(3000);
server.close((err) => {
  console.log("server closed");
  process.exit(err ? 1 : 0);
});

to call server.close to close the server.

We call it with a callback that’s called when the server is closed.