Key- Value Table help required

Store the NSArray/NSMutableArray as the value in the dictionary.

 

multiset in STL?

Ok, so how do you use this thing? Is it set up statically at the beginning (of something) and then accessed by key to get that array? Is it dynamically created, where things get added (by key) to the arrays? The former is what jiminaus posted. The latter might be better done by defining your own class either as a subclass of NSMutableDictionary (or uses a NSMutableDictionary) to stores NSMutableArrays in the dictionary.

That's reasonably straightforward. Modify the setObject:forKey to append the object to current result of the objectForKey: (if there is one) or create a new NSMutableArray if there isn't one. Create new methods for other operations (if you want to delete an object from one of the arrays, you could define a removeObject:forKey: method).

I'm not sure why the documentation recommends against subclassing, but for a simple specialization like you describe it seems pretty safe.

<100 lines of code, 2 files, depending on how many operations you need.

 

Not, it's not safe. NSDictionary is a class cluster.