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

范例

Example #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'));
?>

以上例程会输出：

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

User Contributed Notes

goran at extensionsforjoomla dot com 09-Jul-2007 03:52


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.