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# serialize

(PHP 3 >= 3.0.5, PHP 4, PHP 5)

serialize -- Generates a storable representation of a value

## Description

string serialize ( mixed value )

serialize() returns a string containing a byte-stream representation of `value` that can be stored anywhere.

This is useful for storing or passing PHP values around without losing their type and structure.

To make the serialized string into a PHP value again, use unserialize(). serialize() handles all types, except the resource-type. You can even serialize() arrays that contain references to itself. Circular references inside the array/object you are serialize()ing will also be stored. Any other reference will be lost.

When serializing objects, PHP will attempt to call the member function __sleep() prior to serialization. This is to allow the object to do any last minute clean-up, etc. prior to being serialized. Likewise, when the object is restored using unserialize() the __wakeup() member function is called.

> Note: This didn't work correctly until 4.0.7.

> Note: In PHP 3, object properties will be serialized, but methods are lost. That limitation was removed in PHP 4 as both properties and methods are now restored. Please see the Serializing Objects section of Classes and Objects for more information.

> It is not possible to serialize PHP built-in objects.

Example 1. serialize() example

`<?php
// $session_data contains a multi-dimensional array with session
// information for the current user. We use serialize() to store
// it in a database at the end of the request.
$conn = odbc_connect("webdb", "php", "chicken");
$stmt = odbc_prepare($conn,
"UPDATE sessions SET data = ? WHERE id = ?");
$sqldata = array (serialize($session_data), $PHP_AUTH_USER);
if (!odbc_execute($stmt, &$sqldata)) {
$stmt = odbc_prepare($conn,
"INSERT INTO sessions (id, data) VALUES(?, ?)");
if (!odbc_execute($stmt, &$sqldata)) {
/* Something went wrong.. */
}
}
?>`

See Also: unserialize().

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