ios - Error with segue: 'NSInvalidArgumentException', reason: 'Receiver has no segue with identifier -

i'm getting error app: terminating app due uncaught exception 'nsinvalidargumentexception', reason: 'receiver (<viewcontroller: 0x17e60c10>) has no segue identifier 'datetimestring''. code this:

viewcontroller.m

 -(ibaction) alarmsetbuttontapped:(id)sender {      nsdateformatter *dateformatter = [[nsdateformatter alloc] init];     dateformatter.timezone = [nstimezone defaulttimezone];     [dateformatter setdateformat:@"dd:mm:yyyy:ss:mm:hh"];     nsstring *datetimestring = [dateformatter stringfromdate: datetimepicker.date ];     nslog( @"alarm set : %@", datetimestring );       nsdateformatter *dateformatter1 = [[nsdateformatter alloc] init];     [dateformatter setdateformat:@"dd:mm:yyyy:ss:mm:hh"];     nsdate *datetimeseconds = [[nsdate alloc] init];     datetimeseconds = [dateformatter1 datefromstring:datetimestring];     nstimeinterval seconds = [[nsdate date] timeintervalsincedate:datetimepicker.date];     nslog(@"seconds %.f", seconds);      nsstring *path = [nsstring stringwithformat:@"%@/alarm-clock.m4a", [[nsbundle mainbundle] resourcepath]];     nsurl *soundurl = [nsurl fileurlwithpath:path];     _alarmplayer = [[avaudioplayer alloc] initwithcontentsofurl:soundurl error:nil];     [_alarmplayer playattime: _alarmplayer.devicecurrenttime + seconds];      nslog( @"alarm set button tapped : %@", datetimestring );      [self schedulelocalnotificationwithdate: datetimepicker.date];     [self performseguewithidentifier:@"datetimestringsegue" sender: nil];     [self presentmessage:(@"alarm succesfully set %@",datetimestring)]; }  -(ibaction)alarmcancelbuttontapped:(id)sender {     nslog( @"alarm cancel button tapped");      [[uiapplication sharedapplication] cancelalllocalnotifications];      [self presentmessage:@"alarm canceled lazy pants!"];  }  - (void)prepareforsegue:(uistoryboardsegue *)segue sender:(id)sender {     viewcontroller3 *tvc = segue.destinationviewcontroller;     nslog(@"prepareforsegue: %@", segue.identifier);     if ([[segue identifier] isequaltostring:@"datetimestringsegue"])     {         tvc.datetimestring = (@"%@",_datetimestring);         nslog(@"segue");     } } 

viewcontroller.h

@interface viewcontroller : uiviewcontroller <avaudioplayerdelegate> {     iboutlet uidatepicker *datetimepicker; }  @property nsinteger numberofloops; @property(readonly) nstimeinterval devicecurrenttime; @property (strong, nonatomic) avaudioplayer *alarmplayer; @property (strong, nonatomic) nsstring *datetimestring;   - (nstimeinterval)timeintervalsincedate:datetimepicker;  -(void) presentmessage: (nsstring *) message; -(void) schedulelocalnotificationwithdate: (nsdate *) firedate; -(ibaction) alarmsetbuttontapped:(id)sender; -(ibaction) alarmcancelbuttontapped:(id)sender; - (bool)playattime:(nstimeinterval)time;  @end 

seguedestination.h

#import "viewcontroller.h"  @interface viewcontroller3 : uiviewcontroller  @property(nonatomic, readonly) nsuinteger tapcount; @property nsinteger numberofloops; @property(readonly) nstimeinterval devicecurrenttime; @property (strong, nonatomic) avaudioplayer *alarmplayer; @property (strong, nonatomic) nsstring *datetimestring; @property (strong, nonatomic) iboutlet uilabel *datetimepicker;  - (nstimeinterval)timeintervalsincedate:datetimepicker; - (bool)playattime:(nstimeinterval)time;  - (ibaction)iconsbtn:(id)sender;   @end 

seguedestination.m

#import "viewcontroller.h"  @interface viewcontroller3 () {     avaudioplayer *_alarmplayer; } @end  @implementation viewcontroller3  - (void)viewdidload {     [super viewdidload]     self.view.backgroundcolor = [uicolor colorwithpatternimage:[uiimage imagenamed:@"wwv5.jpg"]];   }  - (void) buttontouchdownrepeat:(id)sender event:(uievent *)event {     uitouch *touch = [[event alltouches] anyobject];     if(touch.tapcount == 3) {         nslog(@"twice");     }     else         nslog(@"ughhhhh"); }  - (ibaction)iconsbtn:(id)sender {  } 

i'm trying access datetimestring in 2nd viewcontroller whenever click button supposed send app terminates error. first time i've attempted use segue , i'm not going great it. once error sorted able call datetimestringin 2nd viewcontrollerand value set in 1st viewcontroller?

thanks!

edit: have done identifier in storyboard.

in storyboard need set identifier segue: