active classname with hooks
const SideBar = () =>{
const [activeClass, setClass] = useState('');
return (
<div className="sidebar">
<ul>
<li> <Link onClick={() => setClass('active')} className={activeClass} to="/"> Home </Link> </li>
<li> <Link to="/about"> About </Link> </li>
<li> <Link to="/form"> Form </Link> </li>
</ul>
</div>
)
}