Advanced PHP for Web Professionals

Starting a Session

You cannot track variables across a user session unless you start the session on each page on which you want to use or alter those variables. Starting a session uses the session_start() function:

session_start(); 

session_start() takes no arguments. If you are starting a new session, then the function initializes the session and creates the necessary temp files to track the session. If a $PHPSESSID is found by the function, either by a cookie or a GET variable, then the function resumes the current session and the page has access to any variables that have been registered to the session.

Once you have started the session, you need to register some variables with it. The session will not track variables until they have been ...