What are some other data structures that use hashing?

Category : Java | Sub Category : Java Interview questions | By Prasad Bonam Last updated: 2023-08-03 13:56:15 Viewed : 322

Hashing is a fundamental technique used in various data structures to efficiently store, retrieve, and manage data. Some other data structures that use hashing include:

1. HashSet: As mentioned earlier, HashSet is a collection that uses hashing to store unique elements. It internally uses a HashMap to store elements with hash codes as keys and null values.

2. LinkedHashSet: LinkedHashSet is similar to HashSet but maintains the insertion order of elements. It combines hashing with a linked list to achieve both constant-time insertion, deletion, and retrieval, as well as predictable iteration order.

3. HashMap: A HashMap is a key-value store that uses hashing to map keys to their corresponding values. It is an efficient data structure for quick retrieval of values based on keys.

4. LinkedHashMap: LinkedHashMap is a combination of a hash table and a linked list. It maintains the insertion order of keys, allowing predictable iteration. This data structure is useful when order matters.

5. HashTable: HashTable is a synchronized version of a HashMap in Java, making it thread-safe. It uses hashing to store key-value pairs.

6. ConcurrentHashMap: ConcurrentHashMap is an advanced version of a HashMap designed for concurrent access by multiple threads. It uses a combination of hashing and separate partitions to ensure thread-safety.

7. IdentityHashMap: IdentityHashMap is a specialized HashMap that uses reference equality (rather than equals()) to compare keys. It is useful when you want to use object references as keys.

8. WeakHashMap: WeakHashMap is a special HashMap that uses weak references for its keys. This means that keys that are not strongly referenced anywhere else can be garbage collected, making this data structure useful for scenarios where automatic key removal is needed.

9. Bloom Filter: A Bloom filter is a probabilistic data structure that uses hashing to efficiently test the membership of an element in a set. It allows for fast lookups but may have false positives (indicating an element is present when it is not) due to its space efficiency.

10. Cuckoo Hashing: Cuckoo hashing is a technique that resolves hash collisions by using multiple hash functions and alternate hash table locations. It is used to implement hash tables with a fixed number of slots.

These are some of the commonly used data structures that rely on hashing to achieve fast access and management of data. Each data structure has its specific use cases and performance characteristics, making them suitable for different scenarios.