SplObjectStorage::getHash
(PHP 5 >= 5.4.0, PHP 7)
SplObjectStorage::getHash — Calculate a unique identifier for the contained objects
Description
$object
) : stringThis method calculates an identifier for the objects added to an SplObjectStorage object.
The implementation in SplObjectStorage returns the same value as spl_object_hash().
The storage object will never contain more than one object with the same identifier. As such, it can be used to implement a set (a collection of unique values) where the quality of an object being unique is determined by the value returned by this function being unique.
Examples
Example #1 SplObjectStorage::getHash() example
<?php
class OneSpecimenPerClassStorage extends SplObjectStorage {
public function getHash($o) {
return get_class($o);
}
}
class A {}
$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";
?>
The above example will output something similar to:
2 3
English translation
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Document created the 30/01/2003, last modified the 26/10/2018
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References
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