# Countable # [OuterIterator interface](https://www.php.net/manual/zh/class.outeriterator.php) > 实现OuterIterator的类可用于迭代迭代器 ## 接口摘要 ``` <pre class="calibre17">``` OuterIterator extends <span class="token4">Iterator</span> <span class="token3">{</span> <span class="token">/* 方法 */</span> public getInnerIterator <span class="token3">(</span> void <span class="token3">)</span> <span class="token3">:</span> Iterator <span class="token">//返回当前条目的内部迭代器</span> <span class="token">/* 继承的方法 */</span> abstract public Iterator<span class="token3">:</span><span class="token3">:</span>current <span class="token3">(</span> void <span class="token3">)</span> <span class="token3">:</span> mixed abstract public Iterator<span class="token3">:</span><span class="token3">:</span>key <span class="token3">(</span> void <span class="token3">)</span> <span class="token3">:</span> scalar abstract public Iterator<span class="token3">:</span><span class="token3">:</span>next <span class="token3">(</span> void <span class="token3">)</span> <span class="token3">:</span> void abstract public Iterator<span class="token3">:</span><span class="token3">:</span>rewind <span class="token3">(</span> void <span class="token3">)</span> <span class="token3">:</span> void abstract public Iterator<span class="token3">:</span><span class="token3">:</span>valid <span class="token3">(</span> void <span class="token3">)</span> <span class="token3">:</span> bool <span class="token3">}</span> ``` ```