Reading and Writing Sessions

 <?php   session_start();   echo 'Sessions activated.<br />';   $_SESSION['version'] = phpversion();   echo 'Session data written.<br />';   echo "Session data read: {$_SESSION['version']}."; ?> 

All session data is accessible from a PHP script via the $_SESSION array. Because the data itself is stored on the server-side, you can write session data and read it in the next PHP statement, without the requirement of a round-trip to the server as it was with cookies. Just remember to call session_start() first and then access $_SESSION. The preceding listing creates a session file that Figure 5.6 shows.

Figure 5.6. The content of the session file created by Listing 5.16.