js格式化时间

<script>
    function dateFormatter(value) {
        var str="";
        if(value){
            var date=new Date(value);
            var year = date.getFullYear();
            var month = (date.getMonth() + 1)< 10 ? "0" + (date.getMonth() + 1) : date.getMonth() + 1;
            var d = date.getDate()< 10 ? "0" + date.getDate() : date.getDate();
            var hour = date.getHours() < 10 ? "0" + date.getHours() : date.getHours();
            var minute = date.getMinutes() < 10 ? "0" + date.getMinutes() : date.getMinutes();
            var second = date.getSeconds() < 10 ? "0" + date.getSeconds() : date.getSeconds();
            str=year + "年" + month + "月" + d + "日 " + hour + ":" + minute + ":" + second;
        }
        return str;
    }

    alert(dateFormatter(new Date()));

</script>