RUNOOB.COM
源代码：
点击运行
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>菜鸟教程(runoob.com)</title> </head> <body> <p>如果时间早于 20:00，会获得问候 "Good day"。</p> <button onclick="myFunction()">点击这里</button> <p id="demo"></p> <script> function myFunction(){ var x=""; var time=new Date().getHours(); if (time<20){ x="Good day"; } document.getElementById("demo").innerHTML=x; } </script> </body> </html>
运行结果