ArrayObject::offsetExists()

(PHP 5, PHP 7)

Returns whether the requested index exists

说明

publicArrayObject::offsetExists(mixed $index): bool

参数

$index

The index being checked.

返回值

TRUE if the requested index exists, otherwise FALSE

范例

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'));
?>

以上例程会输出：

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

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.