代码示例:(标识:jquery_dom_attr_callback)
<!DOCTYPE html>
<html>
<head>
<script src="/jquery/jquery-1.11.1.min.js"></script>
<script>
$(document).ready(function(){
  $("button").click(function(){
    $("#w3s").attr("href", function(i,origValue){
      return origValue + "/jquery.html"; 
    });
  }); 
});
</script>
</head>

<body>
<p><a href="https://www.sucainiu.com" id="w3s">素材牛</a></p>
<button>改变 href 值</button>
<p>请把鼠标指针移动到链接上,或者点击该链接,来查看已经改变的 href 值。</p>
</body>
</html>
运行结果: