title: Is this a php variable variable bug?
body: <p>Is there a logical explanation to this?</p>
  
  <pre><code>&lt;?php  
  $$a = 'hello world';  
  echo $$a; //displays hello world  
  echo $$aa; //displays hello world  
  echo $$aaa; //displays hello world  
  ?&gt;
  </code></pre>