title: how to iterate a result of jquery selector
body: <p>I want to iterate a result of query selector.</p>
  
  <p>Html code</p>
  
  <pre><code>&lt;nav id="navigation"&gt;
          &lt;a href="#" tabindex="1" class="active_nav"&gt;nav1&lt;/a&gt;
          &lt;a href="#" tabindex="2"&gt;nav2&lt;/a&gt;
          &lt;a href="#"tabindex="3"&gt;nav3&lt;/a&gt;
  &lt;/nav&gt;
  </code></pre>
  
  <p>when I use javascript</p>
  
  <pre><code>alert($("#navigation &gt;a")[0]);
  </code></pre>
  
  <p>the result is the tag <code>a</code> href attribute
  I don't know why.</p>