代码引入:<script src=‘jquery.js‘></script>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>选择器使用</title>
</head>
<body>
<div id="box">
<ul>
<li><a href="#"><span>1</span></a></li>
<li><a href="#"><span>2</span></a></li>
<li><a href="#"><span>3</span></a></li>
<li><a href="#"><span>4</span></a></li>
</ul>
<ul>
<li><a href="#"><span>1</span></a></li>
<li><a href="#"><span>2</span></a></li>
<li><a href="#"><span>3</span></a></li>
<li><a href="#"><span>4</span></a></li>
</ul>
</div>
</body>
<script src="https://cdn.bootcss.com/jquery/3.5.0/jquery.min.js "></script>
<script>
//id选择器
var box = $("#box");
console.log(box);
//class选择器
var Lists = $(".list");
console.log(Lists);
//标签选择器
var aliLi = $("li");
console.log(aliLi);
//子级选择器
var firstListli = $(".list:eq(0)>li");
console.log(firstListli);
//后代选择器
var allSpan = $(".list:eq(1) span");
console.log(allSpan);
</script>
</html>
原文:https://www.cnblogs.com/dongxuelove/p/12933278.html