Hash Table/Associative Array in VBA

Question

I can't seem to find the documentation explaining how to create a hash table or associative array in VBA. Is it even possible?

Can you link to an article or better yet post the code?

Answer 1

I've used Francesco Balena's HashTable class several times in the past when a Collection or Dictionary wasn't a perfect fit and i just needed a HashTable.

Answer 2

I think you are looking for the Dictionary object, found in the Microsoft Scripting Runtime library. (Add a reference to your project from the Tools...References menu in the VBE.)

It pretty much works with any simple value that can fit in a variant (Keys can't be arrays, and trying to make them objects doesn't make much sense. See comment from @Nile below.):

Dim d As dictionary Set d = New dictionary  d("x") = 42 d(42) = "forty-two" d(CVErr(xlErrValue)) = "Excel #VALUE!" Set d(101) = New Collection 

You can also use the VBA Collection object if your needs are simpler and you just want string keys.

I don't know if either actually hashes on anything, so you might want to dig further if you need hashtable-like performance. (EDIT: Scripting.Dictionary does use a hash table internally.)