title: Display none a div if a element (span) inside this div is empty
body: <p>I would like set <code>display: none</code> on a <code>div</code> if a <code>span</code> element inside this div is empty.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="mydiv test1"&gt;
    &lt;img src="https://upload.wikimedia.org/wikipedia/commons/thumb/3/30/Googlelogo.png/1200px-Googlelogo.png" width="100px"&gt;
    &lt;span id="myid"&gt;&lt;/span&gt;
  &lt;/div&gt;
  &lt;div class="mydiv test2"&gt;
    &lt;img src="https://upload.wikimedia.org/wikipedia/commons/thumb/3/30/Googlelogo.png/1200px-Googlelogo.png" width="100px"&gt;
    &lt;span id="myid"&gt;100&lt;/span&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>In this example I would like to set <code>display: none</code> on the first <code>div</code>. How can I do this using jQuery?</p>