What's the Point of (NSError**)error?

Question

Example: The -save: method of NSManagedObjectContext is declared like this:

- (BOOL)save:(NSError **)error

Since

Answer 1

If you just passed in a pointer, all the method could do would alter the already existing NSError object that you are pointing to.

By passing in a pointer to a pointer, it can create new NSError objects and leave you with a pointer that points to them.