逻辑应该没有错啊，为什么连秒数都没减

源自：8-17 编程练习

逻辑应该没有错啊，为什么连秒数都没减

<!DOCTYPE html>

<html>

<head>

<title>浏览器对象</title>

</head>

<body>

<p>

<b id = "countDown">3</b>秒后回到主页<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.href="https://www.baidu.com"；

}

}else{

clearInterval("jump()");

}
}

setInterval("jump()",1000);

function goBack(){

window.history.back();

}

</script>

</body>

</html>

提问者：qq__3259 2018-06-28 23:19

个回答

qq_丿iTTF鹰_0: 2018-06-29 11:49:18

已采纳

<!DOCTYPE html>

<html>

<head>

    <title>浏览器对象</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>秒后回到主页<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>

问题自减是--num；

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