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iOS

Posted by Matthew Ong
Matthew Ong
6,041 Points

App fails to compile after adding readonly attribute (Build a Simple iPhone App (iOS7) > Refactoring into a Model > Readonly Attribute)

If you try to run the app after finishing this video, it fails to compile. In the THCrystallBall.m file I get an error whenever using _predictions that says Use of undeclared identifier '_predictions'

Upon deleting the readonly attribute from the predictions property, the errors go away and the app once again works. Did I miss something?

2 Answers

Amit Bijlani
STAFF
Amit Bijlani
Treehouse Guest Teacher
Amit Bijlani
Amit Bijlani
Treehouse Guest Teacher

Since the property is declared as readonly an instance variable is not being created for you. So one needs to be manually created.

Modify the the header of THCrystalBall.h to:

@interface THCrystalBall : NSObject {
    NSArray *_predictions;
}

Sorry about it, I will be modifying the video next week to address this issue.

Matthew Ong
Matthew Ong
6,041 Points
Matthew Ong
Matthew Ong
6,041 Points

Thanks for your quick reply! Your videos are very helpful, thanks so much for doing this series :)