SPL Functions
The follow function is a implementation of the PHP´s function spl_object_hash(), unavailable in versions less 5.2.0.
But, the algorithm of this function is different of the original PHP´s function.
(Sorry... my english is very bad...)
<?php
if (!function_exists('spl_object_hash')) {
/**
* Returns the hash of the unique identifier for the object.
*
* @param object $object Object
* @author Rafael M. Salvioni
* @return string
*/
function spl_object_hash($object)
{
if (is_object($object)) {
ob_start(); var_dump($object); $dump = ob_get_contents(); ob_end_clean();
if (preg_match('/^object\(([a-z0-9_]+)\)\#(\d)+/i', $dump, $match)) {
return md5($match[1] . $match[2]);
}
}
trigger_error(__FUNCTION__ . "() expects parameter 1 to be object", E_USER_WARNING);
return null;
}
}
?>
spl_object_hash
(PHP 5 >= 5.2.0)
spl_object_hash — Return hash id for given object
Description
string spl_object_hash
( object $obj
)
This function returns an unique identifier for the object. This id can be used as a hash key for storing objects or for identifying an object.
Parameters
- object
-
Any object.
Return Values
A string that is unique for each object and is always the same for the same object.
Examples
Example #1 A spl_object_hash() example
<?php
$id = spl_object_hash($object);
$storage[$id] = $object;
?>
add a note
User Contributed Notesspl_object_hash
Rafael M. Salvioni
04-Dec-2008 07:01
04-Dec-2008 07:01
planetbeing
05-Jul-2007 11:40
05-Jul-2007 11:40
Note that the contents (properties) of the object are NOT hashed by the function, merely its internal handle and handler table pointer. This is sufficient to guarantee that any two objects simultaneously co-residing in memory will have different hashes. Uniqueness is not guaranteed between objects that did not reside in memory simultaneously, for example:
var_dump(spl_object_hash(new stdClass()), spl_object_hash(new stdClass()));
Running this alone will usually generate the same hashes, since PHP reuses the internal handle for the first stdClass after it has been dereferenced and destroyed when it creates the second stdClass.