Description: Selects all elements that are the only child of their parent.
If the parent has other child elements, nothing is matched.
<!DOCTYPE html>
<html>
<head>
<style>
div { width:100px; height:80px; margin:5px; float:left; background:#b9e }
</style>
<script src="https://code.jquery.com/jquery-latest.js"></script>
</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>
<script>$("div button:only-child").text("Alone").css("border", "2px blue solid");</script>
</body>
</html>
[ <li>Glen</li> ]