通用选择器选择文档中所有可用的元素。使用方法如下：
$('*')您可以尝试运行以下代码以了解如何在jQuery中实现通用选择器-
<html>
<head>
<title>jQuery Universal Selector</title>
<script src = "https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script>
<script>
$(document).ready(function() {
/* This would select all the elements */
$("*").css("background-color", "yellow");
});
</script>
</head>
<body>
<div class = "big" id = "div1">
<p>This is first division of the DOM.</p>
</div>
<div class = "medium" id = "div2">
<p>This is second division of the DOM.</p>
</div>
<div class = "small" id = "div3">
<p>This is third division of the DOM</p>
</div>
</body>
</html>