Hello guys I am new to Xcode/iOS developing I trying to add json data to the mutable array , and it results in app crash :( so far here is my code: if(! [defaults objectForKey:@"Person1"]) [defaults setObject:[PersonsFromSearch objectAtIndex:index] forKey:@"Person1"]; else { NSMutableArray *Array = [[NSMutableArray alloc]init]; id object = [defaults objectForKey:@"Person1"]; Array = [object isKindOfClass:[NSArray class]] ? object : @[object]; [Array addObject:[PersonsFromSearch objectAtIndex:index]];//crash here :(( [Array moveObjectFromIndex:[Array count] toIndex:0]; } Crash Dump: * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFDictionary addObject:]: unrecognized selector sent to instance 0xbf98dc0' what is wrong here ? can you please help me to resolve this issue Array contains this (Json?) { Address = "\U05d3\U05e8\U05da \U05d4\U05e9\U05dc\U05d5\U05dd 53"; CellPhone = "052-3275381"; EMail = "[email protected]"; EnglishPerson = "Yehuda Konfortes"; FaceBookLink = ""; Fax1 = "03-7330703"; Fax2 = ""; FileNAme = "100050.jpg"; HomeEMail = ""; HomeFax = ""; HomePhone1 = ""; HomePhone2 = ""; PersonID = 100050; PersonName = "\U05d9\U05d4\U05d5\U05d3\U05d4 \U05e7\U05d5\U05e0\U05e4\U05d5\U05e8\U05d8\U05e1"; Phone1 = "03-7330733"; Phone2 = ""; ZipCode = ""; }