Question

Can someone tell me why I am getting

Undefined symbols for architecture i386:
"_OBJC_CLASS_$_ScramblerModel", referenced from:
objc-class-ref in ViewController.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

My project is at This zip

Answer 1

Your code clearly is referencing this ScramblerModel class, but you haven’t included the ScramblerModel.m file in your project.

So, first, if you look at your Compile Sources, it says:

Go ahead and click on the “+” button at add your model. You probably want to do this for ScramblerPlayer, too, because you use that class, as well, so if you don’t add that as well, you’ll get another linker error.

Second, don’t forget to tell the app what storyboard to use:

Third, your .h has instance variables (ivars) defined for all of your IBOutlet properties. This is a problem, because your @synthesize statement is instantiating ivars with a leading underscore, but your .h (and your code) are referring to duplicative ivars that aren’t hooked up to anything. For example, you have a property remainingTime, you have a @synthesize remainingTime = _remainingTime (which is creating a _remainingTime ivar). So your explicitly declared ivar remainingTime isn’t connected to your remainingTime property, and thus no user interface updates will result if you use that ivar, despite the similar name.

You can fix the problem and simplify your code by (a) getting rid of the explicitly declared ivars for your properties; and (b) change your code to reference the property, e.g. self.remainingTime or the ivar _remainingTime. So, your .h is simplified and becomes:

//
//  ViewController.h
//  Scrambler
//
//  Created by Alex Grossman on 8/26/12.
//  Copyright (c) 2012 Alex Grossman. All rights reserved.
//

#import <UIKit/UIKit.h>

@class ScramblerModel;

@interface ViewController : UIViewController{
    ScramblerModel* gameModel;
    NSTimer* gameTimer;
}
@property (weak, nonatomic) IBOutlet UILabel *high;
@property (weak, nonatomic) IBOutlet UIBarButtonItem *skipButton;
@property (weak, nonatomic) IBOutlet UIBarButtonItem *restartButton;
@property (weak, nonatomic) IBOutlet UILabel *playerScore;
@property (weak, nonatomic) IBOutlet UILabel *remainingTime;
@property (weak, nonatomic) IBOutlet UILabel *scrambledWord;
@property (weak, nonatomic) IBOutlet UITextField *guessTxt;

-(IBAction)guessTap:(id)sender;
-(IBAction)restart:(id)sender;
-(IBAction)skip:(id)sender;
-(IBAction)category:(id)sender;
-(void) endGameWithMessage:(NSString*) message;

@end

When you compile your project, you’ll get lots of errors, though, because your code was erroneously referencing those old, redundant (and misnamed) ivars. Thus, for example, in your viewDidLoad you had lines like:

remainingTime.text = [NSString stringWithFormat:@"%i", gameModel.time];
playerScore.text = [NSString stringWithFormat:@"%i", gameModel.score];

Those should be:

self.remainingTime.text = [NSString stringWithFormat:@"%i", gameModel.time];
self.playerScore.text = [NSString stringWithFormat:@"%i", gameModel.score];

Just repeat this correction to everywhere you were referring to the erroneous ivars.