You can use the spread operator (...) or the functional setState update.
Example:
import { useState } from 'react';
function App() {
const [items, setItems] = useState([1, 2, 3]);
const addItem = () => {
setItems(prevItems => [...prevItems, 4]); // Adding new element
};
return (
<div>
<button onClick={addItem}>Add Item</button>
<ul>
{items.map((item, index) => <li key={index}>{item}</li>)}
</ul>
</div>
);
}
export default App;