[IOS] Timestamp and string time conversion __ios

[IOS] timestamp vs. String time conversion

Timestamp of the current time + (NSString *) cnowtimestamp{nsdate *newdate = [NSDate Date];
    long int timesp = (long) [Newdate timeIntervalSince1970];
    NSString *temptime = [NSString stringwithformat:@ "%ld", Timesp];
return temptime; }//timestamp--String time    + (nsstring *) Cstringfromtimestamp: (nsstring *) timestamp{     Methods of    //time stamping        nsdate *timedata = [nsdate  dateWithTimeIntervalSince1970:[timestamp intValue]];        nsdateformatter *dateformatter =[[nsdateformatter alloc] init];        [dateformatter setdateformat:@ "yyyy year mm month DD Day  hh:mm"];        nsstring *strtime = [dateformatter stringfromdate:timedata];        return strTime;  }  //String time--timestamp    + (nsstring *) Ctimestampfromstring: (nsstring *) thetime{       //thetime __@ "%04d-%02d-%02d %02d:%02d:00"               //for timestamp         NSDateFormatter *formatter = [[NSDateFormatter alloc] init];        [formatter setDateStyle:NSDateFormatterMediumStyle];        [formatter setTimeStyle:NSDateFormatterShortStyle];       [formatter  setdateformat:@ "Yyyy-mm-dd hh:mm:ss"];       //         nstimezone* timezone = [nstimezone timezonewithname:@ "Asia/ Beijing "];       //        [formatter  setTimeZone:timeZone];       nsdate* datetodo = [formatter  datefromstring:thetime];       nsstring *timesp = [nsstring stringwithformat:
@ "%ld",  (long) [datetodo timeintervalsince1970]];         
     return timeSp;  }