<!DOCTYPE html> <html lang="en"> <head><meta charset="UTF-8"><title>jq之demo</title><!--线上jq库--><script src="https://code.jquery.com/jquery-3.4.1.min.js"></script><script>$(document).ready(function(){$("button").click(function(){/*function()为回调函数在slow执行完后执行*/$("p").hide("slow",function(){alert("段落隐藏");});});});</script> </head> <body><button>隐藏</button><br/><p>段落</p> </body> </html>