title: Jquery multiple classes with .addClass dynamically
body: <p>I need to use .addCLass on an list of classes, but function classList gives me an array. .addClass doesn't work with array BUT it does  work if i write multiple classes, like ('.class1, class2, class3'). Is there a way to convert the .classList array to a string which can give to .addCLass. I need to get the classList dynamically hence I can't enter them manually... </p>
  
  <p>Thanks</p>
  
  <pre><code>var classList = $('#postitus').attr('class').split(/\s+/).join('.');
  $(classList).addClass('active');
  </code></pre>