SplObjectStorage::getHash

(PHP 5 >= 5.4.0, PHP 7)

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

Descrierea

public SplObjectStorage::getHash ( object $object ) : string

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.

Parametri

object

The object whose identifier is to be calculated.

Valorile întoarse

A string with the calculated identifier.

Erori/Excepții

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

Exemple

Example #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";
?>

Exemplul de mai sus va afișa ceva similar cu:

2
3

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