SplObjectStorage::offsetGet

(PHP 5 >= 5.3.0, PHP 7)

SplObjectStorage::offsetGet — Returns the data associated with an object

说明

public mixed SplObjectStorage::offsetGet ( object $object )

Returns the data associated with an object in the storage.

参数

object: The object to look for.

返回值

The data previously associated with the object in the storage.

错误／异常

Throws UnexpectedValueException when object could not be found.

范例

Example #1 SplObjectStorage::offsetGet() example


<?php
$s = new SplObjectStorage;

$o1 = new StdClass;
$o2 = new StdClass;

$s[$o1] = "hello";
$s->attach($o2);


var_dump($s->offsetGet($o1)); // Similar to $s[$o1]
var_dump($s->offsetGet($o2)); // Similar to $s[$o2]
?>

以上例程的输出类似于：

string(5) "hello"
NULL

参见

SplObjectStorage::offsetSet() - Associates data to an object in the storage
SplObjectStorage::offsetExists() - Checks whether an object exists in the storage
SplObjectStorage::offsetUnset() - Removes an object from the storage

User Contributed Notes

acgrid 03-Jun-2016 03:58


The performance of SplObjectStorage in PHP7.0.7 has boosted a lot.



SplObjectStorage

double(1.3110690116882)

[object_hash => value]

double(2.4147419929504)

kontrollfreak+php at gmail dot com 10-Jul-2015 10:47


SplObjectStorage::offsetGet() can become EXTREMELY slow depending on the associated data (PHP 5.6).



<?php



// SplObjectStorage

$object = new stdClass;

$test = new SplObjectStorage;

$test->attach($object, str_repeat("\0", 1024*1024));

$start = microtime(true);

for ($i = 0; $i < 1000000; $i++) {

    $test->offsetGet($object);

}

var_dump(microtime(true) - $start); // 76 seconds!



// Array + spl_object_hash()

$object = new stdClass;

$test = [];

$test[spl_object_hash($object)] =  str_repeat("\0", 1024*1024);

$start = microtime(true);

for ($i = 0; $i < 1000000; $i++) {

    $temp = $test[spl_object_hash($object)];

}

var_dump(microtime(true) - $start); // 0.3 seconds