要选择具有多个类的元素，请执行以下操作。在这里，x，y和z是我们的类，
$('.x.y.z')您可以尝试运行以下代码，以了解如何在jQuery中选择具有多个类的元素：
<html>
<head>
<title>jQuery Selector Example</title>
<script src = "https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script>
<script>
$(document).ready(function() {
$(".one.two").css("background-color", "grey");
});
</script>
</head>
<body>
<div class = "one two" id="div">
<p>This is first division of the DOM.</p>
</div>
<div class = "three" id = "div3">
<p>This is third division of the DOM</p>
</div>
</body>
</html>