ArrayObject::offsetGet

(PHP 5, PHP 7, PHP 8)

ArrayObject::offsetGet — 指定したインデックスの値を返す

説明

public ArrayObject::offsetGet(mixed $key): mixed

パラメータ

key: 値のインデックス。

戻り値

指定したインデックスの値、あるいは null を返します。

エラー / 例外

指定したインデックスが存在しない場合に E_NOTICE が発生します。

例

例1 ArrayObject::offsetGet() の例

<?php
$arrayobj = new ArrayObject(array('zero', 7, 'example'=>'e.g.'));
var_dump($arrayobj->offsetGet(1));
var_dump($arrayobj->offsetGet('example'));
var_dump($arrayobj->offsetExists('notfound'));
?>

上の例の出力は以下となります。

int(7)
string(4) "e.g."
bool(false)

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User Contributed Notes 3 notes

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Sam ¶

16 years ago

If you're overloading ArrayObject, it's worth noting that while this method (when implemented by the parent) will return a reference, so code like $fakeArray['foobar']['hello'] = 1; will work like you expect.

However, when you overload the offsetGet method, you CANNOT define it as &offsetGet, so the above code falls out (because it returns the 'foobar' variable before you actually work with it).

This is something that the developers broke between 5.0 and 5.1, and was closed as bogus (http://bugs.php.net/bug.php?id=34783). So this is not a big, or question, or request, but just something worth noting.

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Jason ¶

8 years ago

It's worth noting that the PHP devs *did* fix the issue brought up in Sam's comment in 2013 (per the comment thread in his link here: https://bugs.php.net/bug.php?id=34783#1366088374), since at least PHP 5.3.8.

So, you *can* (and in most cases should) overload offsetGet with reference syntax to get expected functionality:

<?php
class myArrayType extends ArrayAccess {

    public function &offsetGet($index) {
        // ...
    }

}
?>

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Alex Andrienko ¶

15 years ago

Speaking of offsetGet() method overloading, be advised, that if you're iterating through Object via foreach, this method wouldn't be called. Iterator's current() method will be called instead.

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