spl_classes
It seems that when switching scopes, the last one is repeated... Not necessarily a bug, but could create some problems/unexpected behavior
<?php
$var = new stdClass();
var_dump(spl_object_hash($var), spl_object_hash(new stdClass()));
hola();
function hola() {
$var = new stdClass();
var_dump(spl_object_hash($var), spl_object_hash(new stdClass()));
}
/* will output something like
string(32) "f4c9a9e4c63bb94a344b09fa90b57d5c"
string(32) "7b6e43337944619e217ded14a7a78d35"
string(32) "7b6e43337944619e217ded14a7a78d35"
string(32) "ebd1bf725146297194bb011ef5e9c4d5"
*/
?>
spl_object_hash
(PHP 5 >= 5.2.0)
spl_object_hash — 指定したオブジェクトのハッシュ ID を返す
説明
string spl_object_hash
( object $obj
)
この関数は、オブジェクトの一意な識別子を返します。この ID は、 オブジェクトを保存する際のハッシュのキーとして使用できますし、 オブジェクトを識別するための値として使用することもできます。
パラメータ
- object
-
何らかのオブジェクト。
返り値
各オブジェクトに固有で、同一オブジェクトに対しては常に同じ値となる文字列を返します。
例
例1 spl_object_hash() の例
<?php
$id = spl_object_hash($object);
$storage[$id] = $object;
?>
add a note
User Contributed Notesspl_object_hash
markus dot albe at mailinator dot com
16-Nov-2009 07:53
16-Nov-2009 07:53
test user
14-Oct-2009 12:15
14-Oct-2009 12:15
It is possible to mark objects with unique identity to establish required functionality:
<?php
if (!function_exists('spl_object_hash')) {
function spl_object_hash($object) {
if (!is_object($object)) {
trigger_error(__FUNCTION__ . "() expects parameter 1 to be object", E_USER_WARNING);
return null;
}
if (!isset($object->__oid__))
$object->__oid__ = uniqid();
}
return $object->__oid__;
}
}
?>
SlappyTheFish
28-May-2009 10:12
28-May-2009 10:12
With regards to the previous post, I'm not entirely sure that easy does do it. Consider the following code:
<?php
class Testy
{
public $something;
public function __toString()
{
return serialize($this);
}
}
$objOne = new Testy();
$objOne->something = "hello";
$objTwo = new Testy();
$objTwo->something = "hello";
printf("objOne:\n");
printf("Bad way: %s\n", md5((string)$objOne));
printf("SPL Way: %s\n", spl_object_hash($objOne));
printf("objTwo:\n");
printf("Bad way: %s\n", md5((string)$objTwo));
printf("SPL Way: %s\n", spl_object_hash($objTwo));
?>
The spl_object_hash function returns a hash based on the particular object, not the content. The spl hash will always be the same for a given object, regardless of content.
andi.rein(AT)gmx de
15-Apr-2009 11:48
15-Apr-2009 11:48
Easy does it
<?php
if (!function_exists('spl_object_hash')) {
/**
* Returns the hash of the unique identifier for the object.
*
* @param object $object
* @author Andreas Rein
* @return string
*/
function spl_object_hash($object) {
if (is_object($object)) {
return md5((string)$object);
}
trigger_error(__FUNCTION__ . "() expects parameter 1 to be object", E_USER_WARNING);
return null;
}
}
?>
Rafael M. Salvioni
04-Dec-2008 07:01
04-Dec-2008 07:01
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;
}
}
?>
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.