jquery 选择器 :only-child-优快云博客

:only-child

匹配集合中子集里仅仅只有一个元素的元素。返回匹配元素集合

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
                    "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
  <script src="http://code.jquery.com/jquery-latest.js"></script>
  
  <script>
  $(document).ready(function(){
    $("div button:only-child").text("Alone").css("border", "2px blue solid");
  });
  </script>
  <style>
  div { width:100px; height:80px; margin:5px; float:left; background:#b9e }
  </style>
</head>
<body>
  <div>
    <button>Sibling!</button>
    <button>Sibling!</button>
  </div>
  <div>
    <button>Sibling!</button>
  </div>
  <div>
    None
  </div>
  <div>  
    <button>Sibling!</button>
    <button>Sibling!</button>
    <button>Sibling!</button>
  </div>
  <div>
    <button>Sibling!</button>
  </div>
</body>
</html>

$("div button:only-child").text("Alone").css("border", "2px blue solid");

匹配div中包含button元素的button元素集合，且该集合里面只有一个元素的button集合。以下是匹配元素集合

<button>Sibling!</button>
<button>Sibling!</button>