Get first child of the first child of each element in an array
<p>I've built an array of <code>table</code> elements matching a specific criterion using <code>querySelectorAll()</code>, but I'd like to conditionally create a new, separate array containing the first child of the first child of each of those elements.<br>
However, I'm not sure how to do this.
My array currently looks like this:</p>

<pre><code>var arr = [
    &lt;table class="matchedCriterion"&gt;…&lt;/table&gt;,
    &lt;table class="matchedCriterion"&gt;…&lt;/table&gt;
];
</code></pre>

<p>Is there a way for me to run <code>querySelector()</code> or <code>querySelectorAll()</code> on each element, matching what I want using <code>:first-child:first-child</code></p>
