CODE EXAMPLE FOR JAVASCRIPT

link tag react

<Link to={`/users/${user.id}`} activeClassName="active">{user.name}</Link>
// becomes one of these depending on your History and if the route is
// active
<a href="/users/123" class="active">Michael</a>
<a href="#/users/123">Michael</a>

// change the activeClassName
<Link to={`/users/${user.id}`} activeClassName="current">{user.name}</Link>

// change style when link is active
<Link to="/users" style={{color: 'white'}} activeStyle={{color: 'red'}}>Users</Link>