Send asynchronous browser requests with fetch, XMLHttpRequest, JSON, errors, and progressive UI.
Lessons
Keep core fetch and request patterns at your fingertips.
AJAX Cheatsheet is easiest to learn by reading the example, changing it, and observing the result.
async function loadLessons() {
const response = await fetch('/api/lessons', {
headers: { 'Accept': 'application/json' }
});
if (!response.ok) {
throw new Error(`HTTP ${response.status}`);
}
return response.json();
}
loadLessons()
.then(lessons => console.log(lessons))
.catch(error => console.error('Failed to load:', error.message));Practice the AJAX Cheatsheet example in a small scratch file, then explain what changed and why.