ArrayObject::offsetExists

(PHP 5, PHP 7, PHP 8)

ArrayObject::offsetExists — Returns whether the requested index exists

说明

public ArrayObject::offsetExists(mixed $key): bool

参数

key

The index being checked.

返回值

true if the requested index exists, otherwise false

示例

示例 #1 ArrayObject::offsetExists() example

<?php
$arrayobj = new ArrayObject(array('zero', 'one', 'example'=>'e.g.'));
var_dump($arrayobj->offsetExists(1));
var_dump($arrayobj->offsetExists('example'));
var_dump($arrayobj->offsetExists('notfound'));
?>

以上示例会输出：

bool(true)
bool(true)
bool(false)

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goran at extensionsforjoomla dot com
17 years ago
In versions prior to PHP 5.2.2 offsetExists() would return false if index value is null.
<?php
// running PHP 5.2.1
$params = new ArrayObject(array('INT'=>null, 'STR'=> null, 'BOOL'=>null, 'LOB'=>null));
$test = $params->offsetExists('INT');
var_dump($test);
// result would be bool(false)
// running PHP 5.2.2
$params = new ArrayObject(array('INT'=>null, 'STR'=> null, 'BOOL'=>null, 'LOB'=>null));
$test = $params->offsetExists('INT');
var_dump($test);
// result would be bool(true)
?>
Both tests where made on Windows platform.
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备份地址：http://www.lvesu.com/blog/php/arrayobject.offsetexists.php