51help TIY
码：
<!DOCTYPE html> <html> <body> <p>于 20:00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>
查看结果: