<!DOCTYPE?html>
<html>?
<head>??
<title>瀏覽器對象</title>????
<meta?http-equiv="Content-Type"?content="text/html;?charset=gkb"/>????
</head>?
<body>??
<!--先編寫好網頁布局-->??
<h1>操作成功</h1>??
<span?id="one">5</span>??
<span>秒后</span>??<a?href="javascript:sea()">返回</a>??
<script?type="text/javascript">???
function?daojishi()?{
var?sn=document.getElementById("one").innerHTML
if(sn==0){
window.open("http://www.baidu.com") } ?
setTimeout("daojishi()",1000); ?
sn--;
document.getElementById("one").innerText=sn;?}?
function?sea()?{?
window.history.back();?
}??
?//獲取顯示秒數的元素，通過定時器來更改秒數。?????
?//通過window的location和history對象來控制網頁的跳轉。????
?</script>??
?<button?id="id1"?onclick="daojishi()">開始倒計時</button>
??</body>
??</html>
2020-01-20
因為這條語句：setTimeout("daojishi()",1000);
網頁自動執行daojishi()這個函數了，不需要按鈕