10.3.5 Ending a session: session_destroy()This is NOT the latest copy of this book; click here for the latest version.
bool session_destroy ( void )
A session lasts until your visitor closes their browser - if they navigate away to another page, then return to your site without having closed their browser, their session will still exist . This behaviour is usually desirable - potentially your visitor's session data might last for days, as long as they keep browsing around your site, whereas cookies usually have a fixed lifespan.
If you want to explicitly end a user's and delete their data without them having to close their browser, you need to clear the $_SESSION array, then use the session_destroy() function. Session_destroy() removes all session data stored on your hard disk, leaving you with a clean slate.
To end a session and clear up its data, use this code:
<?php
session_start();
$_SESSION = array();
session_destroy();
?>
There are two important things to note there: firstly, session_start() is called so that PHP loads the user's session, and secondly we use an empty call to the array() function to make $_SESSION an empty array - effectively wiping it. If session_start() is not called, neither of the following two lines will work properly, so, again, always call session_start()!
|
Want to see this stuff in print? PHP in a Nutshell takes the core topics covered here, adds in thousands of edits from the editorial team and myself, and combines them to make an unbeatable reference for PHP programmers at all levels.
My latest book has hundreds more tips on how to use PHP, Apache, and MySQL, plus Perl, Python, shell scripts, performance tuning, and more!
|
