为什么结果是NaN

源自：7-4 返回星期方法

<!DOCTYPE HTML>

<html >

<head>

<title>系好安全带,准备启航</title>

var date=new Date() ;

var year=date.getFullYear();

var month=date.getMonth()+1;

var day=date.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 week=date.getDay();

document.write(year+"年"+month+"月"+day+"日"+" "+weekday[week])

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 score=new Array();

score1=scoreStr.split(';');

var sum=0;

for(var i=0;i<score1.length;i++){

var score2=new Array();

score2=score1[i].split(':');

sum+=parseInt(score2[i]);

}

document.write("<br><br>总分数："+sum);

document.write("<br><br>平均分："+Math.round(sum/(score1.length)));

</script>

</head>

<body>

</body>

</html>

提问者：叛逆春 2015-08-03 11:34