Question

I am somewhat lost on how to declare properties in my Singleton. Should I use strong or weak? Particularly I have an NSMutableArray property and I am not sure what to do. Can someone explain in some what detail?

Thanks

Answer 1

This has nothing to do with Singletons, and depends entirely on how your array is being used. Is it private? Public? Readonly? Readwrite? It just depends on ownership, like everything else. If your singleton owns the array, use strong or copy. Otherwise use weak.

That said, it’s not typically a good idea to directly expose a mutable collection at all. If you only need other classes to be able to read it, use an NSMutableArray internally, and expose an NSArray copy publicly. If other classes need to mutate the collection, it’s better practice to expose a set of KVC-compliant methods that mutate an internal mutable array.