SplObjectStorage::offsetGet
(PHP 5 >= 5.3.0, PHP 7, PHP 8)
SplObjectStorage::offsetGet — Returns the data associated with an object
说明
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
示例 #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
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User Contributed Notes 2 notes
acgrid ¶
6 years ago
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 ¶
6 years ago
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
备份地址：http://www.lvesu.com/blog/php/splobjectstorage.offsetget.php