js 时间戳格式化日期格式

时间戳转换为日期，网上搜了好几个或多或少都有点问题，自己整理了一下，写了个方法

console.log(formatDate(1565280000000))

输出:

 2019-08-09 00:00:00

Date.prototype.format =function(datetime)
{
       var date = new Date(datetime);//时间戳为10位需*1000，时间戳为13位的话不需乘1000
                var year = date.getFullYear(),
                    month = ("0" + (date.getMonth() + 1)).slice(-2),
                    sdate = ("0" + date.getDate()).slice(-2),
                    hour = ("0" + date.getHours()).slice(-2),
                    minute = ("0" + date.getMinutes()).slice(-2),
                    second = ("0" + date.getSeconds()).slice(-2);
                // 拼接
                var result = year + "-"+ month +"-"+ sdate +" "+ hour +":"+ minute +":" + second;
                // 返回
                return result;
}

formatDate(datetime) {
                var date = new Date(datetime);//时间戳为10位需*1000，时间戳为13位的话不需乘1000
                var year = date.getFullYear(),
                    month = ("0" + (date.getMonth() + 1)).slice(-2),
                    sdate = ("0" + date.getDate()).slice(-2),
                    hour = ("0" + date.getHours()).slice(-2),
                    minute = ("0" + date.getMinutes()).slice(-2),
                    second = ("0" + date.getSeconds()).slice(-2);
                // 拼接
                var result = year + "-"+ month +"-"+ sdate +" "+ hour +":"+ minute +":" + second;
                // 返回
                return result;
            }