php 对象的自定义遍历

class myIterator implements Iterator {

private $position = 0;

private $array = array(

"firstelement",//7、遍历第一个元素

"secondelement",

"lastelement",

);

???public function __construct() {//2、实例化时自动调用构造方法

???????　　$this->position = 0;//给position赋值为0

???}

???function rewind() {//3、遍历对象之前 先重置指针

???????var_dump(__METHOD__);

???????$this->position = 0;//将position属性设置为0

???}

???function current() {//5、获取当前指针

???????　　var_dump(__METHOD__);

???????　　return $this->array[$this->position];//设置当前的指针指向firstelement

???}

???function key() {//6、获取当前的键值

???????　　var_dump(__METHOD__);

???????　　return $this->position;//返回当前键的值 ?为0

???}

???function next() {//8、指针下移

???????　　var_dump(__METHOD__);

???????　　++$this->position;//position+1

???}

???function valid() {//4、判断指针是否合法

???????　　var_dump(__METHOD__);

???????　　return isset($this->array[$this->position]);//判断array数组的指针是否合法 返回bool

???}

}

$it = new myIterator;//1、实例化 myIterator类

foreach($it as $key => $value) {//遍历该对象

???var_dump($key, $value);//

???echo "\n";

}