Javascript 将YYYYMMDDHMMSS格式化为YYYY/MM/DD HH:MM:SS

是否有一种简单的方法将字符串“YYYYMMDDHHMMSS”转换为“YYYY/MM/DD HH:MM:SS”

比如我有

var date_string = "20121231023350";

我希望输出为

new_date_string = "2012/12/31 02:33:50";

使用诸如或之类的库

这两种方法中的任何一种都会使日期Javascript的处理/解析/格式化变得非常困难

"20121231023350".replace(
    /^(\d{4})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})$/,
    "$1/$2/$3 $4:$5:$6");  // "2012/12/31 02:33:50"

function ConvertTime(OldTime)
{
    if(OldTime.length != 14)
        return "Error";

    return OldTime.substring(0,4) + "/" + OldTime.substring(4,6) + "/" + OldTime.substring(6,8) + " " + OldTime.substring(8,10) + ":" + OldTime.substring(10,12) + ":" + OldTime.substring(12,14);
}

ConvertTime("20121231023350");