data structures using is said to occur similarlykeys and also collide the main goal of using hash function is to reduce the range of array indices that have to be handled thusinstead of having valueswe just need valuesthereby reducing the amount of storage space required universe of keys ( actual keys ( figure actual keys (kfigure null null null null direct relationship between key and index in the array universe of keys (uk null null null null null relationship between keys and hash table index hash functions hash function is mathematical formula whichwhen applied to keyproduces an integer which can be used as an index for the key in the hash table the main aim of hash function is that elements should be relativelyrandomlyand uniformly distributed it produces unique set of integers within some suitable range in order to reduce the number of collisions in practicethere is no hash function that eliminates collisions completely good hash function can only minimize the number of collisions by spreading the elements uniformly throughout the array in this sectionwe will discuss the popular hash functions which help to minimize collisions but before thatlet us first look at the properties of good hash function properties of good hash function low cost the cost of executing hash function must be smallso that using the hashing technique becomes preferable over other approaches for exampleif binary search algorithm can search an element from sorted table of items with log key comparisonsthen the hash function must cost less than performing log key comparisons determinism hash procedure must be deterministic this means that the same hash value must be generated for given input value howeverthis criteria excludes hash functions that depend