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ArrayObject::offsetExists

(PHP 5, PHP 7)

ArrayObject::offsetExistsReturns whether the requested index exists

说明

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

参数

index

The index being checked.

返回值

true if the requested index exists, otherwise false

范例

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'));
?>

以上例程会输出:

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

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1位用户评论

[#1] ▲0▼ goran@extensionsforjoomla.com [50%] (2007-07-09 03:52:35)

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.