session_start(); $sessionId = generateUniqueID(); $_SESSION['session_id'] = $sessionId;
$orderNumber = generateUniqueID(); $userId = 1234; $orderDetails = array( 'order_number' => $orderNumber, 'user_id' => $userId, // more details );This function belongs to the PHP Standard Library as it is built-in to the language and does not require any additional external packages or libraries.