developer-roadmap/src/data/roadmaps/datastructures-and-algorithms/content/103-basic-data-structures/104-hash-tables.md

Hash Tables

Hash Tables are specialized data structures that allow fast access to data based on a key. Essentially, a hash table works by taking a key input, and then computes an index into an array in which the desired value can be found. It uses a hash function to calculate this index. Suppose the elements are integers and the hash function returns the value at the unit's place. If the given key is 22, it will check the value at index 2. Collisions occur when the hash function returns the same output for two different inputs. There are different methods to handle these collisions such as chaining and open addressing.