Session

Session support consists of a way to preserve certain data across subsequent accesses to the web server.

By default, each query to a webserver is independent from the others. With session, it is possible to keep some data on the server, and retrieve them at each access.

It relies on the session_* functions, and the $_SESSION superglobal variable.

<?php

    if (isset($_SESSION['x'])) {
        print 'x was already set with the value ' . $_SESSION['x'];
    }
    
    $_SESSION['x'] = rand(0, 10);
    print 'Giving the value ' . $_SESSION['x'] . 'to x, in the session';

?>

Documentation

See Also

• Session in PHP: Creating, Destroying, and Working With Session in PHP
• Sessions security
• Fixing PHP Session Issues: Troubleshooting and Solutions

Related

• Superglobal Variables
• Object Persistence
• Persistence
• Session Fixation
• Session Hijacking
• Horizontal Scaling
• Race Condition
• Single Sign On (SSO)
• State
• JSON Web Token (JWT)
• Load Balancer
• SessionHandlerInterface
• SessionIdInterface
• SessionUpdateTimestampHandlerInterface
• APCu
• Shared Memory
• Temporary
• Time To Live (TTL)