if( ) { }后面的大括号为什么要去掉？？
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>new Boolean()</title>
</head>
<body>
<script type="text/javascript">
function fn(arguments){
var num= 0,m=0;
for (var i=0;i<arguments.length;i++){
if(typeof(arguments[i])!="number"){
continue;
num += arguments[i];
m++;
}
}
num=num/m;
return num;
}
alert(fn(1,2,4,5,6));
</script>
</body>
</html>
