TCS Change Manager Interview Questions and Answers

Hashmap is key-value pair collection while Hashset is a unique value collection.

• Hashmap allows duplicate values but not duplicate keys while Hashset only allows unique values.

• Hashmap uses key to access values while Hashset uses object reference.

• Hashmap is faster for accessing values while Hashset is faster for checking if a value exists.

• Example: Hashmap - {1: 'apple', 2: 'banana', 3: 'apple'}, Hashset - {'apple', 'bana

Hashmap is a data structure that stores key-value pairs and uses hashing to locate values based on their keys.

• Hashmap uses an array to store the key-value pairs

• The key is hashed to generate an index in the array

• If multiple keys hash to the same index, a linked list is used to store them

• Hashmap provides constant time complexity for insertion, deletion, and retrieval of values

• Java's HashMap class is an implementation of