:first
概述
获取匹配的第一个元素
:last
概述
获取匹配的最后个元素
<!DOCTYPE html><html> ???<head> ???????<meta charset="UTF-8"> ???????<script type="text/javascript" src="js/jquery-3.1.1.min.js" ></script> ???????<title></title> ???????<style> ???????????.main{ ???????????????color: #FF0000; ???????????????font-weight: bold; ???????????} ???????</style> ???????<script> ???????????$(document).ready(function(){ ???????????????//first获取匹配的第一个元素 ???????????????$("button:first").click(function(){ ???????????????????$("p:first").addClass("main"); ???????????????}); ???????????????//last获取匹配的最后个元素 ???????????????$("button:last").click(function(){ ???????????????????$("p:last").removeClass("main"); ???????????????}); ???????????}); ???????</script> ???</head> ???<body> ???????<p>第一个段落。</p> ???????<p class="main">第二个段落。</p> ???????<button>addClass</button> ???????<button>removeClass</button> ???</body></html>jQuery选择器--:first和:last
原文地址：https://www.cnblogs.com/fengfuwanliu/p/10054422.html