JS时间戳转时间格式

    //转化为时间格式
    function getDate(timestamp) {
        timestamp = timestamp.replace("/Date(", "").replace(")/", "");
        if (timestamp.indexOf("+") > ) {
            timestamp = timestamp.substring(, timestamp.indexOf("+"));
        }
        else if (timestamp.indexOf("-") > ) {
            timestamp = timestamp.substring(, timestamp.indexOf("-"));
        }
        let date = new Date(parseInt(timestamp, ));
        let year = date.getFullYear();
        let month = date.getMonth() +  <  ? /*"0" +*/ (date.getMonth() + ) : date.getMonth() + ;
        let currentDate =( date.getDate() <  ? /*"0" + */date.getDate() : date.getDate())+" ";
        let Hours = date.getHours() <  ? /*"0" + */date.getHours() : date.getHours();
        let Minutes = date.getMinutes() <  ? "" + date.getMinutes() : date.getMinutes();
        let Seconds = date.getSeconds() <  ? /*"0" +*/ date.getSeconds() : date.getSeconds();
        return `${year}年${month}月${currentDate}日${Hours}:${Minutes}:${Seconds}`;
    }

网上找了好多都不行。。。