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

User Contributed Notes

depoemarc at swap dot fn dot ln dot googlemail dot com 25-Jun-2015 02:47


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

*/

?>