任意數求和

<script type="text/javascript">
    var total=null;
    function sum() {
        for(var i=0;i<arguments.length;i++){
            if (typeof arguments[i]=="number" && !isNaN(arguments[i])){
                total+=Number(arguments[i]);
            }
            //total+=!isNaN(arguments[i])?Number(arguments[i]):0;
        }
        return total
    }
    sum(1,2,[],'',{a:1},true)
    console.log(total);
</script>