时间格式化

    Date.prototype.format =   function (fmt){
            var o = {
               "M+":this.getMonth()+1,
                "d+":this.getDate(),
                "h+":this.getHours(),
                "m+":this.getMinutes(),
                's+':this.getSeconds(),
            }
            if(/(y+)/.test(fmt)) fmt = fmt.replace(RegExp.$1,(this.getFullYear()+'').substr(4-RegExp.$1.length));
            for (var k in o) {
                if(new RegExp("("+k+")").test(fmt)){
                    fmt = fmt.replace(RegExp.$1,(RegExp.$1.length == 1)?(o[k]):(("00"+o[k]).substr((""+o[k]).length)))
                } 
            }
            return fmt
        }
   
        let time = new Date().format("yy-MM-dd hh:mm:ss"