【ul】
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-1.9.1.js'></script>
<script type='text/javascript'>
$(window).load(function(){
console.log( $('ul li.active').index() + 1 );
});
</script>
</head>
<body>
<ul>
<li>1</li>
<li class="active">2</li>
<li>3</li>
<li>4</li>
<ul>
</body>
</html>
