Changing an object which is used as a Map key

Question

Let V be a class with a single attribute named K and its getter and setters.

What\'s supposed to happen if I do:

V v = new V();
v.setK(\"a\");
HashMa         


        

Answer 1

If you were trying to look up the map using v.getk() it wouldn't find an entry, because you've changed the value return by the getter on v.

Or in other words, the map isn't magically kept in sync with what happens to your v object - it uses (and keeps using) the value given to it in the put().