The conversation between human and AI assistant.
How is Hashmap in Java implemented internally? What are the pros and cons to use it? What are the complexities it provides for insert, delete and lookup?
Can you explain the complexities that Hashmap provides for insert, delete, and lookup?
Sure! Insert and delete operations in HashMap involve calculating the hash code of the key to determine the index at which to insert or delete the value. If multiple keys have the same hash code, then they will be stored in the same bucket and a collision resolution strategy needs to be employed. This can increase the complexity of the operation and the time taken to complete it. For lookup, however, the complexity is constant time as it involves only calculating the index of the bucket and retrieving the value stored there.