Selectors/API/jQuery - Sample Code
:only-child
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<script src="/jquery/js/jquery.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>
[実行結果]