title: PHP &$string - What does this mean?
body: <p>I've been googling but I can't find anything. </p>
  
  <pre><code>$x-&gt;func(&amp;$string, $str1=false, $str2=false);
  </code></pre>
  
  <p>what does that <code>&amp;</code> before <code>$string</code> <code>&amp;$string</code> do?</p>