迭代器模式(Iterator Pattern) 又叫做游标模式(Cursor Pattern)

百度词条的解释

http://baike.baidu.com/view/1413849.htm

<?php
//迭代器模式
//抽象聚集
interface IList {

	function getIterator();

}

//抽象迭代器
interface IIterator {

	function moveNext();

	function currentItem();

	function first();

	function nexts();

}

//具体聚集
class ConcreteList implements IList {

	private $list = array();

	public function __construct() {
		$this->list = array(1,2,3,4,5);
	}

	public function getIterator() {
		return new ConcreteIterator($this);
	}

	public function length() {
		return count($this->list);
	}

	public function getElement($index) {
		return $this->list[$index];
	}

}

//具体迭代器
class ConcreteIterator implements IIterator {

	private $list;

	private $index;

	public function __construct(ConcreteList $list) {
		$this->list = $list;
		$this->index = 0;
	}

	public function moveNext() {
		return $this->index < $this->list->length() ? true :false;
	}

	public function currentItem() {
		return $this->list->getElement($this->index);
	}

	public function first() {
		$this->index = 0;
	}

	public function nexts() {
		if($this->index < $this->list->length()) {
			$this->index++;
		}
	}

}

$list = new ConcreteList();
$iterator = $list->getIterator();
while($iterator->moveNext()) {
	$i = $iterator->currentItem();
	echo $i."<br/>";
	$iterator->nexts();
}
?>