Руководство jQuery

$("div#result1").append($("p:first").hasClass("selected").toString());
$("div#result2").append($("p:last").hasClass("selected").toString());
$("div#result3").append($("p").hasClass("selected").toString());

"HTML"

<p>Hello</p>
  <p class="selected">Goodbye</p>
  <div id="result1">First paragraph has selected class: </div>
  <div id="result2">Last paragraph has selected class: </div>
  <div id="result3">Some paragraph has selected class: </div>

"CSS"

 p { margin: 8px; font-size:16px; }
  .selected { color:red; }
  .highlight { background:yellow; }

"Живой пример jQuery"

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
						"http://www.w3.org/TR/html4/loose.dtd">
	<html>
	<head>
	<link href="http://test-drupal.ru/themes/slyweb/css/jqueryiframe.css" 
	rel="stylesheet" type="text/css"/>
	  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.5.0/jquery.min.js"></script>
	<script>
	  $(document).ready(function(){
	
$("div#result1").append($("p:first").hasClass("selected").toString());
$("div#result2").append($("p:last").hasClass("selected").toString());
$("div#result3").append($("p").hasClass("selected").toString());


	  });
	</script>

	</head>
	<body class="iframe">

	
<p>Hello</p>
  <p class="selected">Goodbye</p>
  <div id="result1">First paragraph has selected class: </div>
  <div id="result2">Last paragraph has selected class: </div>
  <div id="result3">Some paragraph has selected class: </div>



	</body>
	</html>

	
	<style>
	
 p { margin: 8px; font-size:16px; }
  .selected { color:red; }
  .highlight { background:yellow; }


	</style>

Метод появился в jQuery 1.0 (http://api.jquery.com/hasClass/)

Версия jQuery 1.4.2 Документ создан 2010-08-21