SplFixedArray::offsetExists
(PHP 5 >= 5.3.0, PHP 7, PHP 8)
SplFixedArray::offsetExists — Returns whether the requested index exists
说明
Checks whether the requested index index
exists.
参数
index-
The index being checked.
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depoemarc at swap dot fn dot ln dot googlemail dot com ¶
9 years ago
It should be noted that offsetExists behaves like "offsetIsSet" rather than "offsetIsValid":
<?php
$arr = new SplFixedArray(3);
var_dump($arr->offsetExists(1)); // false
$arr[1] = 42; // $arr->offsetSet(1, 42);
var_dump($arr->offsetExists(1)); // true
$arr[1] = null; // $arr->offsetSet(1, null);
var_dump($arr->offsetExists(1)); // true
unset($arr[1]); // $arr->offsetUnset(1);
var_dump($arr->offsetExists(1)); // false
var_dump($arr);
/*
object(SplFixedArray)[1]
null
null
null
*/
?>备份地址：http://www.lvesu.com/blog/php/splfixedarray.offsetexists.php