Forward declaration error in Crystal Ball app

Question

I'm making good progress on the Crystal Ball app but I can't get past a few errors:

1) Receiver type 'AMCrystalBall' for instance message is a forward declaration

2) Receiver 'AMCrystalBall' for class message is a forward declaration

I feel as thought I've doubled-checked the code against the instructors code several times and can't figure out the error. I don't know how much of my code to post, so here it goes...

AMViewController.h --

#import <UIKit/UIKit.h>

@class AMCrystalBall;

@interface AMViewController : UIViewController

@property (strong, nonatomic) IBOutlet UILabel      *predictionLabel;
@property (strong, nonatomic) AMCrystalBall *crystalBall;

- (IBAction)buttonPressed;

@end

AMViewController.m --

#import "AMViewController.h"

@interface AMViewController ()

@end

@implementation AMViewController

- (void)viewDidLoad
{
[super viewDidLoad];
self.crystalBall = [[AMCrystalBall alloc] init];


UIImage *backgroundImage = [UIImage   imageNamed:@"background"];
UIImageView *imageView = [[UIImageView alloc] initWithImage:backgroundImage];
[self.view insertSubview:imageView atIndex:0];
}

- (void)didReceiveMemoryWarning
   {
    [super didReceiveMemoryWarning];
    }

- (IBAction)buttonPressed {
//int random =  arc4random_uniform(self.predictions.count);
//self.predictionLabel.text = [self.predictions objectAtIndex:random];
self.predictionLabel.text = [self.crystalBall randomPrediction];
}

@end

If anyone knows what the problem could be please help! I can post more code if needed, but I figured this was a good start. Thanks for all the help.

Answer 1 · 2014-10-28T03:10:22Z

October 28, 2014 3:10am

I'm most certain that you're getting those errors because you're using @class instead of an import statement.

Replace this line:

@class AMCrystalBall;

with this one:

#import "AMCrystalBall"

Your errors should go away :)

Answer 2 · 2014-10-28T02:19:00Z

October 28, 2014 2:19am

From what I'm finding on Google for that type of error... everything seems to be pointing to needing to import header files. Without seeing all of the other .h/.m files you have, I would suggest to double check that you're importing the header files everywhere you need to be... and double check camel-case spelling, sometimes it's easier to overlook.

Let me know what you find.

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Forward declaration error in Crystal Ball app

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