The language of behaviour. JavaScript reacts to the user, changes the page, talks to servers and powers every interactive thing on the web.
JavaScript updates the page over time. This clock refreshes every second using setInterval and the Date object.
As you type, JS filters a list in real time — the everyday magic behind every search box.
Add and remove items — JS creates and destroys DOM elements on the fly.
Pick a transform and watch map, filter and reduce reshape the data live.
JS listens for events. Move your mouse inside the box — it follows you and reports coordinates.
JavaScript can draw. Click to scatter a fresh burst of animated circles, and roll a random colour.
setInterval, DOM manipulation, event listeners, array methods and the Canvas API. The shared CSS shell provides the page styling.