[managedObjectContext executeFetchRequest:fetchRequest error:nil]
returns an (immutable) NSArray
, and mutableCopy
creates a - well - mutable copy
of that array. It does not copy the managed objects in the array or the context.
It just allows you to modify self.notes
, e.g. to add, delete or rearrange the objects
in the mutable array.
Remark: If you display objects from a Core Data fetch request in a table view
then you should have a look at NSFetchedResultsController
. It might look a bit more
complicated at the beginning, but allows (for example) automatic updates of the
table view if objects are inserted, deleted or modified.