title: PHP: using empty() for empty string?
body: <p>I recently discovered this interesting <a href="http://kunststube.net/isset/" rel="noreferrer">article</a> by <a href="https://stackoverflow.com/users/476/deceze">Deceze</a>.<br>
  But I'm a bit confused by one of its advises:</p>
  
  <blockquote>
    <p>never use empty or isset for variables that should exist</p>
  </blockquote>
  
  <p>Using <code>empty()</code> is not good choice to test if <code>$foo = '';</code> is empty?</p>