title: toggleClass and remove class from all other elements
body: <p>How can I toggleClass and remove class from all other elements?
  Consider a div that contains a tags:
  html:</p>
  
  <pre><code>&lt;div class="size"&gt;
     &lt;a href=""&gt;blahblah&lt;/a&gt;
     &lt;a href=""&gt;blahblah&lt;/a&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>jQuery:</p>
  
  <pre><code> $(".size a").click(function(){
   $(this).toggleClass('checked');
   if($(".size a").hasClass('checked')){
       $(this).removeClass('checked');
    }
   })
  </code></pre>
  
  <p>I want to add class "cheched" to element and remove the class "ckeched" from other elements that have class "checked" . My code remove all classes. How can I add specific class and remove other element's class with click?
  Thanks in advance</p>