The EmptyIterator class

(PHP 5 >= 5.1.0, PHP 7)

简介

The EmptyIterator class for an empty iterator.

类摘要

EmptyIterator implements Iterator {
/* 方法 */
public mixed current ( void )
public scalar key ( void )
public void next ( void )
public void rewind ( void )
public bool valid ( void )
}

Table of Contents

User Contributed Notes

Ben 20-Jun-2017 09:42
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();
        }
    }

}
?>