title: merge two list of elements returned by querySelectorAll
body: <p>I want to merge two list of elements returned by document.querySelectorAll</p>
  
  <p>below is what i have tried but it is not good:</p>
  
  <pre><code>var ca = document.querySelectorAll(".classA");
      ca = ca + document.querySelectorAll(".classB");
  </code></pre>
  
  <p>I need to merge the list of elements because I need to use just one list in the FOR loop:</p>
  
  <pre><code>for(var i=0; i&lt;ca.length; i++) console.log(ca[i].tagName);
  </code></pre>
  
  <p>How to merge two of such lists correctly ?</p>