Advanced PHP for Web Professionals

Unregistering Session Variables

You may find that some of the session variables that you register are only needed on a few pages and not across an entire site. You can unregister these variables so that they are no longer tracked with the session. This is done using the session_unregister() function:

session_unregister(STRING); 

The STRING argument is the name of the variable that you want to unregister from the session. Note that using session_unregister doesn't delete the contents of the variable on the current page. However, the variable value will not be passed to other pages in the session once it has been deleted from the session file.

You may also want to first check to see if the variable is even registered by using the session_is_registered() ...