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邏輯應(yīng)該沒有錯(cuò)啊，為什么連秒數(shù)都沒減

<!DOCTYPE html>

<html>

?<head>

? <title>瀏覽器對(duì)象</title>??

? <meta http-equiv="Content-Type" content="text/html; charset=gkb"/>? ?

?</head>

?<body>

<p>

? <b id = "countDown">3</b>秒后回到主頁<a href="javascript:goBack();">返回</a>? ?

</p>?

? ?var seconds = document.getElementById("countDown");

? var num = 3;

function jump(){

? ? ? if(num>0){

? ? ? ? num--;

? ? ? ? seconds.innerHTML = num;

? ? ? ? if(num == 1){

? ? ? ? ? window.location.；

? ? ? ? }

? ? ? }else{

? ? ? ? clearInterval("jump()");

??}
}

setInterval("jump()",1000);

? function goBack(){

? ? window.history.back();

? }? ?

?</script>?

</body>

</html>

qq__3259

2018-06-28

源自：JavaScript進(jìn)階篇 8-17

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2 回答

qq_丿iTTF鷹_0 回答被采納 +2 積分
2018-06-29

<!DOCTYPE?html>

<html>

<head>

????<title>瀏覽器對(duì)象</title>

????<meta?http-equiv="Content-Type"?content="text/html;?charset=utf-8"/>

</head>

<body>

<h2>操作成功！</h2>

<p>

????<b?id?=?"countDown">3</b>秒后回到主頁<a?href="javascript:goBack();">返回</a>

</p>

<script??type="text/javascript">

????var?num?=?document.getElementById("countDown").innerHTML;



????function?jump(){
????????--num;
????????document.getElementById("countDown").innerHTML=num;
????????if(num>0){

????????????if(num?==?1){

????????????????window.location.assign("https://www.baidu.com");

????????????}

????????}else{

????????????clearInterval("jump()");
????????}
????}

????setInterval("jump()",1000);

????function?goBack(){

????????window.history.back();

????}

</script>

</body>




</html>

問題自減是--num；

這里?var seconds = document.getElementById("countDown");