NoRewindIterator クラス

    (PHP 5 >= 5.1.0, PHP 7, PHP 8)

    はじめに

    このイテレータは巻き戻しの操作を無視します。 これにより、一部のみを走査する 複数の foreach ループでイテレータを処理することが可能になります。

    クラス概要

    class NoRewindIterator extends IteratorIterator {
    /* メソッド */
    public function __construct(Iterator $iterator)
    public function current(): mixed
    public function key(): mixed
    public function next(): void
    public function rewind(): void
    public function valid(): bool
    /* 継承したメソッド */
    public function IteratorIterator::current(): mixed
    public function IteratorIterator::getInnerIterator(): ?Iterator
    public function IteratorIterator::key(): mixed
    public function IteratorIterator::next(): void
    public function IteratorIterator::rewind(): void
    public function IteratorIterator::valid(): bool
    }

    目次

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    User Contributed Notes 1 note

    up
    5
    Anonymous
    6 years ago
    As its name implies, NoRewindIterator doesn't invoke the "rewind" method when It reaches the end of the iterator.

Let's demonstrate it by two examles.

In this example the "rewind" method will be invoked after when the "foreache" reaches its end, so, we can repeat printing the same values as many times as we want:

<?PHP
$iterator = new ArrayIterator(['PHP', 'Python', 'Go']);

foreach ($iterator as $item) {
    echo $item.PHP_EOL;
}

foreach ($iterator as $item) {
    echo $item.PHP_EOL;
}
?>

By using the NoRewindIterator, the "rewind" won't be invoked, so, we can't do as we did in previous example:

<?PHP
$iterator = new ArrayIterator(['PHP', 'Python', 'Go']);
$iterator = new NoRewindIterator($iterator);

foreach ($iterator as $item) {
    echo $item.PHP_EOL;
}

// doesn't do anything
foreach ($iterator as $item) {
    echo $item.PHP_EOL;
}

?>
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