Hash Tree in Java

The HashMap and LinkedHashMap classes implement the Map interface, whereas TreeMap implements the Map , NavigableMap , and SortedMap interface . A HashMap is implemented as a Hash table, a TreeMap is implemented as a Red-Black Tree, and LinkedHashMap is implemented as a doubly-linked list buckets in Java.

One of the major differences between HashMap and Hashtable is that HashMap is non-synchronized whereas Hashtable is synchronized , which means Hashtable is thread-safe and can be shared between multiple threads but HashMap can not be shared between multiple threads without proper synchronization.

TreeSet stores only one object while TreeMap uses two objects called key and Value . Objects in TreeSet are sorted while keys in TreeMap remain in sorted order. 3. Third difference between TreeSet and TreeMap is that, former implements NavigableSet while later implements NavigableMap in Java.

HashMap is a general purpose Map implementation. It provides a performance of O(1) , while TreeMap provides a performance of O(log(n)) to add, search, and remove items. Hence, HashMap is usually faster .22 May 2019