为JS的Date添加格式化函数

Date.prototype.format = function (format) {
       var o =
            {
                "M+": this.getMonth() + 1,  //month
                "d+": this.getDate(),     //day
                "h+": this.getHours(),    //hour
                "m+": this.getMinutes(),  //minute
                "s+": this.getSeconds(), //second
                "q+": Math.floor((this.getMonth() + 3) / 3),  //quarter
                "S": this.getMilliseconds() //millisecond
            }

       if (/(y+)/.test(format)) {
           format = format.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));
       }

       for (var k in o) {
           if (new RegExp("(" + k + ")").test(format)) {
               format = format.replace(RegExp.$1, RegExp.$1.length == 1 ? o[k] : ("00" + o[k]).substr(("" + o[k]).length));
           }
       }
       return format;
   }

//使用时   new Date().format("yyyy-MM-dd hh:mm:ss");