<!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(){/*chaining方法链接*/$("#p1").css("color","red").slideUp(2000).slideDown(2000);});});</script> </head> <body> <p id="p1">w3c</p> <button>点我</button> </body> </html>