title: How to get elements width by classname using javascript for loop?
body: <p>When i tested it's will be alert <code>blank value</code> and <code>30px</code> 
  I want to get alert <code>400px</code> and <code>30px</code> How can i do ?</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-css lang-css prettyprint-override"><code>.div_cover_threads_image{
    width: 400px;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="div_cover_threads_image"&gt;
  test
  &lt;/div&gt;
  
  &lt;div class="div_cover_threads_image" style="width: 30px;"&gt;
  test
  &lt;/div&gt;
  
  
  &lt;script&gt;     
  var div_cover_threads_image_Elem = document.getElementsByClassName('div_cover_threads_image');
  for(var i=0, len=div_cover_threads_image_Elem.length; i&lt;len; i++)
  {
     alert(div_cover_threads_image_Elem[i].style.width);
  }  
  &lt;/script&gt;</code></pre>
  </div>
  </div>
  </p>