title: Why do I need an empty `content` property on an ::after pseudo-element?
body: <p>I got <a href="http://jsfiddle.net/8p2Wx/2/" rel="noreferrer">http://jsfiddle.net/8p2Wx/2/</a> from a previous question I asked and I see these lines:</p>
  
  <pre><code>.cf:before,
  .cf:after {
      content:"";
      display:table;
  }
  
  .cf:after {
      clear:both;
  }
  </code></pre>
  
  <p>If I take away <code>content:""</code>, it ruins the effect, and I don't understand why it's necessary.</p>
  
  <p>Why is it needed to add an empty <code>content</code> to <code>:after</code> and <code>:before</code> pseudo-elements?</p>