Forum PHP 2017


(PHP 5 >= 5.2.0, PHP 7)

spl_object_hash Devuelve el id del hash del objeto dado


string spl_object_hash ( object $obj )

Esta función devuelve un identificador único del objeto. Este id puede ser empleado como una clave hash para almacenar objetos o para identificar un objeto, siempre que el objeto no sea destruído. Una vez que el objeto se destruye, su hash puede ser reutilizado por otros objetos.



Cualquier objeto.

Valores devueltos

Un string que es único para cada objeto que existe actualmente y que siempre es el mismo para cada objeto.


Ejemplo #1 Ejemplo de spl_object_hash()

$storage[$id] = $object;



Cuando un objeto es destruido, este hash puede ser reutilizado para otros objetos.

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User Contributed Notes 2 notes

9 years ago
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.
mjs at beebo dot org
4 years ago
Note that given two different objects spl_object_hash() can return values that look very similar, and in fact both the most significant *and* least significant digits are likely to be identical!  e.g. "000000003cc56d770000000007fa48c5" and "000000003cc56d0d0000000007fa48c5".

Therefore (especially if using this function for debugging), you may wish to pass the hash into a cryptographic hash function like md5() to get to facilitate visual comparisons, and make it more likely that the first few or last few digits are unique.

md5("000000003cc56d770000000007fa48c5") -> "619a799747d348fa1caf181a72b65d9f"

md5("000000003cc56d0d0000000007fa48c5") -> "ae964bc912281e7804fe5a88b4546cb2"
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