"&" operator in a conditionnal statement
<p>I found this bunch of code in Services_JSON php library:</p>

<pre><code>if ($this-&gt;use &amp; SERVICES_JSON_LOOSE_TYPE) {
    $stk = array(SERVICES_JSON_IN_OBJ);
    $obj = array();
} else {
    $stk = array(SERVICES_JSON_IN_OBJ);
    $obj = new stdClass();
}
</code></pre>

<p>My question is about the first line. What does the single <strong>"&amp;"</strong> operator do?</p>
