JavaScript 实现数码风格时钟：原理与完整代码

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>数码时钟2</title>
 <style type="text/css"> 
 *{
 background-color: rgb(7,110,177);
 vertical-align: middle;
 }
 #div1{
 text-align: center;
 width: 1300px;
 height: 220px;
 margin:0 auto;
 }
 span{
 font-size: 50px;
 color: white;
 }
 </style>
 <script type="text/javascript">
 window.onload=function()
 {
 var aImg = document.getElementsByTagName('img');
 function tick()
 {
  var oDate = new Date();
  var str = toDbl(oDate.getHours())+toDbl(oDate.getMinutes())+toDbl(oDate.getSeconds());
  for (var i = 0; i < aImg.length; i++) {
  aImg[i].src='images/'+str.charAt(i)+'.jpg';
  };
 };
 setInterval(tick,500);
 tick();

 };
 function toDbl(n)
 {
 if (n<10) {
  return '0'+n;
 } else {
  return ''+n;
 }
 };
 </script>
</head>
<body>
 <div id="div1">
 <img src="images/1.jpg">
 <img src="images/2.jpg">
 <span>:</span>
 <img src="images/3.jpg">
 <img src="images/4.jpg">
 <span>:</span>
 <img src="images/5.jpg">
 <img src="images/6.jpg">
 </div>
</body>
</html>