Storing objects in PHP session

In PHP, you can store objects in sessions using the serialize() and unserialize() functions. The serialize() function converts an object into a storable string representation, while unserialize() recreates the object from that string.

Storing Objects in Session

To store an object in a session, first serialize it and then assign it to the $_SESSION superglobal ?

<?php
session_start();
$object = new sample_object();
$_SESSION['sample'] = serialize($object);
?>

The session is started using session_start(), a new object is created, then serialized and stored in the session variable.

Retrieving Objects from Session

To retrieve the stored object, use the unserialize() function ?

<?php
session_start();
$object = unserialize($_SESSION['sample']);
?>

Example − Serialize Array

Here's how serialization works with an array ?

<?php
$data = serialize(array("abc", "defgh", "ijkxyz"));
echo $data;
?>

a:3:{i:0;s:3:"abc";i:1;s:5:"defgh";i:2;s:6:"ijkxyz";}

Example − Serialize and Unserialize

This example demonstrates both serialization and unserialization ?

<?php
$data = serialize(array("abc", "defgh", "ijkxuz"));
echo $data . "<br>";
$test = unserialize($data);
var_dump($test);
?>

a:3:{i:0;s:3:"abc";i:1;s:5:"defgh";i:2;s:6:"ijkxuz";}
array(3) { [0]=> string(3) "abc" [1]=> string(5) "defgh" [2]=> string(6) "ijkxuz" }

Conclusion

Using serialize() and unserialize() allows you to store complex objects in PHP sessions effectively. Always ensure the object's class definition is available when unserializing to avoid errors.