SplObjectStorage
PHP Manual

SplObjectStorage::getHash

(PHP 5 >= 5.4.0)

SplObjectStorage::getHash Calculate a unique identifier for the contained objects

Descrição

public string SplObjectStorage::getHash ( object $object )

This method calculates an identifier for the objects added to an SplObjectStorage object.

The implementation in SplObjectStorage returns the same value as spl_object_hash().

The storage object will never contain more than one object with the same identifier. As such, it can be used to implement a set (a collection of unique values) where the quality of an object being unique is determined by the value returned by this function being unique.

Parâmetros

object

The object whose identifier is to be calculated.

Valor Retornado

A string with the calculated identifier.

Erros

A RuntimeException is thrown when the returned value is not a string.

Exemplos

Exemplo #1 SplObjectStorage::getHash() example

<?php
class OneSpecimenPerClassStorage extends SplObjectStorage {
    public function 
getHash($o) {
        return 
get_class($o);
    }
}
class 
{}

$s = new OneSpecimenPerClassStorage;
$o1 = new stdClass;
$o2 = new stdClass;
$o3 = new A;

$s[$o1] = 1;
//$o2 is considered equal to $o1 so the value is replaced
$s[$o2] = 2;
$s[$o3] = 3;

//these are considered equal to the objects before
//so they can be used to access the values stored under them
$p1 = new stdClass;
$p2 = new A;
echo 
$s[$p1], "\n";
echo 
$s[$p2], "\n";
?>

O exemplo acima irá imprimir algo similar à:

2
3

Veja Também


SplObjectStorage
PHP Manual