邏輯應該沒有錯啊，為什么連秒數(shù)都沒減
<!DOCTYPE html>
<html>
?<head>
? <title>瀏覽器對象</title>??
? <meta http-equiv="Content-Type" content="text/html; charset=gkb"/>? ?
?</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 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>
2018-06-29
<!DOCTYPE?html> <html> <head> ????<title>瀏覽器對象</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");
? var num = 3;
function jump(){
? ? ? if(num>0){
? ? ? ? num--;
? ? ? ? seconds.innerHTML = num;
? ? ? ? if(num == 1){
? ? ? ? ? window.location.；
? ? ? ? }
? ? ? }else{
? ? ? ? clearInterval("jump()");
你獲取了值 但是 你沒處理? 返回的 所以返回的 還是3
2018-07-05
這句話是獲取id而已