在php注销什么更好？

Question

i am having a debate on what would be a better method for loging out in php , if someone could help me clarify i would be most gratefull :

I have two versions of the code for log out

1 )

$logoutGoTo = "login.php";
if (!isset($_SESSION)) {
  session_start();
}
$_SESSION['username'] = NULL;
$_SESSION['user_id'] = NULL;
unset($_SESSION['username']);
unset($_SESSION['user_id']);
$_SESSION = array();
if ($logoutGoTo != "") {header("Location: $logoutGoTo");
exit;

2)

session_start();
    session_unset();
session_destroy();

Which is the better solution?

Answer 1

Generally neither because they both essentially destroy the entire session.

Sessions aren't just for keeping user's logged in. Sessions are used to track other data which may not be linked to a user's account and so you might not want to destroy it when logging out.

Take this for example, you store the language setting in the session. Now the user logs out, you want to keep language setting but logout the user. If you destroy the session then all other data your tracking is destroyed.

I would simply unset/remove the session variables that are keeping the user logged in.