为啥我的代码实现不了啊

源自：7-23 编程练习

<!DOCTYPE HTML>

<html >

<head>

<title>系好安全带,准备启航</title>

var d=new Date();

var year=d.getFullYear();

var month=d.getMonth();

var day=d.getDay();

var weekday=["星期日","星期一","星期二","星期三","星期四","星期五","星期六"];

var mynum=d.getDay();

document.write(year+"年"+month+"月"+day+"日"+weekday[mynum]+"</br>")

//通过javascript的日期对象来得到当前的日期，并输出。

//成绩是一长窜的字符串不好处理，找规律后分割放到数组里更好操作哦

var scoreStr = "小明:87;小花:81;小红:97;小天:76;小张:74;小小:94;小西:90;小伍:76;小迪:64;小曼:76";

var aa=scoreStr.split(";")

var sum=0;

var avg=0;

for{

var i=1;i<=aa.length,i++;

sum = sum + parseInt(aa[i].slice(3,5));}

avg = sum / aa.length;

document.write(parseInt(avg));

</script>

</head>

<body>

</body>

</html>

提问者：是骆驼啊 2016-12-28 21:25