<!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(){/*淡出和淡入之间切换*/$("#div1").fadeToggle();$("#div2").fadeToggle("slow");$("#div3").fadeToggle(3000);});});</script> </head> <body> <p>test</p> <button>点击</button> <br/> <div id="div1" style="width:80px;height:30px;background-color: red;"></div> <div id="div2" style="width:90px;height:30px;background-color: blue;"></div> <div id="div3" style="width:1000px;height:30px;background-color: yellow;"></div> </body> </html>