Performance: Creating an ArrayList from HashMap.values()

Question

Question is how much it costs to create an ArrayList from a HashMap.values() Collection? Or creating the values Collection alone? Assuming Map.size() > 100k. Objects could also

Answer 1

You can create Your own HashMap, that holds the Arraylist collection of values directly (i do not believe that HashMap does it for free, the data structure for it is different). But this requires some additional coding from Your side.