Send asynchronous browser requests with fetch, XMLHttpRequest, JSON, errors, and progressive UI.
Lessons
Call an Express API from the browser.
AJAX with a Node Backend is easiest to learn by reading the example, changing it, and observing the result.
// Client calls an Express endpoint
const res = await fetch('http://localhost:3000/api/lessons');
console.log(await res.json());
/* Server (Express)
app.get('/api/lessons', (req, res) => {
res.json([{ slug: 'ajax-fetch', title: 'fetch API' }]);
});
*/Practice the AJAX with a Node Backend example in a small scratch file, then explain what changed and why.