<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>JS 实时的时间</title> </head> <script> function startTime(){ var today=new Date(); var h=today.getHours(); var m=today.getMinutes(); var s=today.getSeconds();// 在小于10的数字 前加一个‘0’ m=checkTime(m); s=checkTime(s); document.getElementById('txt').innerHTML=h+":"+m+":"+s; t=setTimeout(function(){startTime()},500); } function checkTime(i){ if (i<10){ i="0" + i; } return i; } </script> <body onload="startTime()"> <div id="txt"></div> </body> </html>