React & Modern Frontend (445 Qs)•Part 8: Advanced React Patterns, Portals & Performance (152 - 261)
How do you update rendered elements?
You can update UI(represented by rendered element) by passing the newly created element to ReactDOM's render method.
For example, lets take a ticking clock example, where it updates the time by calling render method multiple times,
javascript
function tick() {
const element = (
<div>
<h1>Hello, world!</h1>
<h2>It is {new Date().toLocaleTimeString()}.</h2>
</div>
);
ReactDOM.render(element, document.getElementById("root"));
}
setInterval(tick, 1000);