设计模式之迭代器模式

<?php/**迭代器模式迭代的使用任何数据类型的数据php提供了两个接口**//** * Interator在内部迭代自己的类的接口 * * Iterator extends Traversable {        abstract public mixed current ( void )        abstract public scalar key ( void )        abstract public void next ( void )        abstract public void rewind ( void )        abstract public boolean valid ( void )    } * *//* * IteratorAggregate  创建外部迭代器的接口 * * IteratorAggregate extends Traversable {        abstract public Traversable getIterator ( void )    } * * * * */class A{    private $_name;    public function __construct($name){        $this->_name = $name;    }}class myIterator implements Iterator{    private $_p;    private $_data;    public function __construct(){        $this->_data = array(new A("apple"), new A("banana"), new A("blow"));        $this->_p = 0;    }    public function current()    {        return array_key_exists($this->_p, $this->_data)                ? $this->_data[$this->_p] : false;    }    public function key()    {        return $this->_p;    }    public function next()    {        $this->_p++;    }    public function rewind()    {        $this->_p = 0;    }    public function valid()    {        return array_key_exists($this->_p, $this->_data);    }}$test = new myIterator();foreach ($test as $key => $value){    echo "$key => ";    var_dump($value);    echo "\n";}class myIterator2 implements IteratorAggregate{    private $_data;    public function __construct()    {        $this->_data = array(new A("apple"), new A("banana"), new A("blow"));    }    public function getIterator()    {        //if $this->_data change with $this it will iterator the property        return new ArrayIterator($this->_data);    }}$test = new myIterator2();foreach ($test as $key => $value){    echo "$key => ";    var_dump($value);    echo "\n";}