ArrayObject::offsetExists

(PHP 5, PHP 7)

ArrayObject::offsetExists — Returns 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)

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.