Detailed explanation of the iterator pattern of PHP design patterns

<?php

/*
 * 迭代器模式
 */
class All implements \Iterator
{
    protected $ids;
    protected $index;

    public function __construct($data)
    {
        $this->ids = $data;
    }

    public function current() //获取当前的元素
    {
        return $this->ids[$this->index];
    }

    public function next() //获取下一个元素
    {
        $this->index++;
    }

    public function valid() //验证当下是否还有下一个元素
    {
        return $this->index < count($this->ids);
    }

    public function rewind() //重置迭代器指针
    {
        $this->index = 0;
    }

    public function key() //迭代器指针的位置
    {
        return $this->index;
    }
}

$arr = [&#39;1&#39;, &#39;2&#39;, &#39;4&#39;]; //客户端
$users = new All($arr);
foreach ($users as $user) {
    var_dump($user);
}