iphone - [__NSCFNumber length]: unrecognized selector sent to instance -

i trying pass data table view controller detail view controller. every entry of table works should, except one. here prepareforsegue method:

- (void)prepareforsegue:(uistoryboardsegue *)segue sender:(id)sender{     if ([[segue identifier] isequaltostring:@"showdetails"]) {         nsindexpath *indexpath = [[self tableview] indexpathforselectedrow];         nsdictionary *notification = [[self notifications] objectatindex:[indexpath row]];         nrdetailviewcontroller *destviewcontroller = [segue destinationviewcontroller];         [destviewcontroller setdate:[notification objectforkey:@"date"]];         [destviewcontroller setfrom:[notification objectforkey:@"from"]];         [destviewcontroller setiden:[notification objectforkey:@"identifier"]];         [destviewcontroller setpriority:[notification objectforkey:@"priority"]];         [destviewcontroller setsubject:[notification objectforkey:@"subject"]];         [destviewcontroller setmessage:[notification objectforkey:@"text"]];      } } 

here interface detail view:

#import <uikit/uikit.h>  @interface nrdetailviewcontroller : uiviewcontroller  @property (weak, nonatomic) iboutlet uitextfield *datefield; @property (weak, nonatomic) iboutlet uitextfield *fromfield; @property (weak, nonatomic) iboutlet uitextfield *idenfield;  @property (weak, nonatomic) iboutlet uitextfield *priofield; @property (weak, nonatomic) iboutlet uitextfield *subjectfield; @property (weak, nonatomic) iboutlet uitextview *messageview;   @property (copy, nonatomic) nsstring *date; @property (copy, nonatomic) nsstring *from; @property (copy, nonatomic) nsstring *iden; @property (copy, nonatomic) nsstring *priority; @property (copy, nonatomic) nsstring *subject; @property (copy, nonatomic) nsstring *message;   @end 

here detail view's implementation file:

#import "nrdetailviewcontroller.h"  @interface nrdetailviewcontroller ()  @end  @implementation nrdetailviewcontroller  - (id)initwithnibname:(nsstring *)nibnameornil bundle:(nsbundle *)nibbundleornil {     self = [super initwithnibname:nibnameornil bundle:nibbundleornil];     if (self) {         // custom initialization     }     return self; }  - (void)viewdidload {     [super viewdidload];     [[self datefield] settext:[self date]];     [[self fromfield] settext:[self from]];     [[self idenfield] settext:[self iden]];     [[self priofield] settext:[self priority]];     [[self subjectfield] settext:[self subject]];     [[self messageview] settext:[self message]];    }  - (void)didreceivememorywarning {     [super didreceivememorywarning];     // dispose of resources can recreated. }  @end 

i have problem setting text of idenfield text of iden. have added exception breakpoint, , got exception indeed occurs @ line:

[[self idenfield] settext:[self iden]]; 

at point, have printed value of [self iden] , contains content want pass, have absolutely no idea problem is, since said, other fields working should.

the exception being thrown is:

2013-08-07 22:28:20.539 notificationreader[1214:11303] -[__nscfnumber length]: unrecognized selector sent instance 0x7587a00 

any appreciated greatly.

it looks like:

[destviewcontroller setiden:[notification objectforkey:@"identifier"]]; 

is returning nsnumber , not nsstring. try replacing line with:

[destviewcontroller setiden:[(nsnumber*)[notification objectforkey:@"identifier"] stringvalue]];