SplFixedArray::offsetExists

(PHP 5 >= 5.3.0, PHP 7, PHP 8)

SplFixedArray::offsetExists — Returns whether the requested index exists

说明

public SplFixedArray::offsetExists(int $index): bool

Checks whether the requested index index exists.

参数

index: The index being checked.

返回值

true if the requested index exists, otherwise false

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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
*/
?>