Java HashSet key/value pair

Question

Why doesn't Java provide functions to get the key/value pairs in a HashSet like exists in Hashtable? It seems like a real pain to have to iterate over it every time you need to get at something. Or is there an easier way to do this?

Answer 1

HashSet doesn't have key/value pairs. It is a Set of objects and you would use an implementer of Set to ensure that a collection of objects contained no duplicates.

Implementers of Map like HashMap have key/value pairs and provide a get(Object key) method to get the value associated with a key.

Answer 2

Since a Set doesn't contain keys and values, there is no way such a view could be provided.

What would you consider to be the key and what would be the value in a Set?