Javascript detect if child of parent element has a class set
<p>This is my code:</p>

<pre><code>&lt;div id="main"&gt;
    &lt;div class="myclass"&gt;&lt;/div&gt;   
&lt;/div&gt;
</code></pre>

<p>How can I detect if inside of <code>main</code>div there is an element with <code>myclass</code> set?</p>

<p>PS. Vanilla JS, no jQuery</p>