我用for后,怎么将数字提出来计算和跟平均值?
<!DOCTYPE HTML>
<html >
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>系好安全带,准备启航</title>
<script type="text/javascript">
//通过javascript的日期对象来得到当前的日期,并输出
var sj = new Date();
var nian = sj.getYear();
var yue = sj.getMonth();
var ri = sj.getDate();
var weekday=["星期日","星期一","星期二","星期三","星期四","星期五","星期六"];
var xq = sj.getDay();
var xqj = weekday[xq];
document.write(nian+"年"+yue+"月"+ri+"日"+" "+xqj);
//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";
for(var i=3;i<=scoreStr.length;i=i+6){
document.write(scoreStr.substr(i,3));
}
//从数组中将成绩撮出来,然后求和取整,并输出。
</script>
</head>
<body>
</body>
</html>