answer How do I redirect if a user visits the login page but is already logged in?

this is session variable

session()->put('user_id',$id);

this is code from login page. I tried to redirect login page if user is already logged in or if session is already created.

<?PHP
session_start();
if(Session::has('YOUR_SESSION_KEY'))
{ 
return view('list');
}?>

but this is code is not giving any result.How can i redirect to list page if i am logged in.