Die Klasse EmptyIterator

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

Einführung

Die Klasse EmptyIterator für einen leeren Iterator.

Klassenbeschreibung

class EmptyIterator implements Iterator {

/* Methoden */

public current(): never

public key(): never

public next(): void

public rewind(): void

public valid(): false

}

Inhaltsverzeichnis

EmptyIterator::current — The current() method
EmptyIterator::key — The key() method
EmptyIterator::next — The next() method
EmptyIterator::rewind — The rewind() method
EmptyIterator::valid — Checks whether the current element is valid

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User Contributed Notes 1 note

down

Ben ¶

7 years ago

Example use case:

<?php
class MyIterator implements IteratorAggregate
{
    /**
     * @var string
     */
    private $url;

    /**
     * MyIterator constructor.
     * @param $url
     */
    public function __construct($url)
    {
        $this->url = $url;
    }

    /**
     * @inheritDoc
     */
    public function getIterator()
    {
        $content = file_get_contents($this->url);
        try {
            return @new SimpleXMLIterator($content);

        } catch (Exception $e) { // Case $content is not valid XML, but you don't care
            return new EmptyIterator();
        }
    }

}
?>

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