Question

Code below:

$_SESSION = array();

Will it clear all session data? If I wouldn’t want to use session_destory().

Answer 1

Yup, it will destroy all session data but not the session itself.

Basically, there’s three elements to a session:

• The session itself, initialized with session_start()
• The session cookie which is set automatically
• Session data which is set via $_SESSION['foo'] = 'bar'

So you are only destroying the session data. session_destroy() destroys both the data and the session itself, but does not remove the session cookie.

The only “real” difference between $_SESSION = array() and session_destroy() is that after session_destroy(), setting session data will not work anymore before initializing a new session.