Runtime

MapputgetcontainsKeynextData Structure
HashMapO(1) ~ O(n)O(1)O(1)O(h / n)Hash Table
LinkedHashMapO(1) ~O(n)O(1)O(1)O(1)Hash Table + Linked List
IdentityHashMapO(1) ~O(n)O(1)O(1)O(h / n)Array
WeakHashMapO(1) ~O(n)O(1)O(1)O(h / n)Hash Table
EnumMapO(1) ~O(n)O(1)O(1)O(1)Array
TreeMapO(log n)O(log n)O(log n)O(log n)Red-black tree
ConcurrentHashMapO(1) ~O(n)O(1)O(1)O(h / n)Hash Tables
ConcurrentSkipListMapO(1) ~O(n)O(log n)O(log n)O(1)Skip List