Introduction - If you have any usage issues, please Google them yourself
Hash (Hash table, also called a hash table), based on key values (Key value) and direct access to the data structure. In other words, it is to access records by key value mapped to a table in a position to accelerate the lookup speed. This mapping function called a hash function to store the recorded array called a hash table. Given Table M, the presence of the function f (key), for any given key value key, if obtained after substituting function records containing that keyword address in the table, called a hash table M (Hash) table, the function f (key) for the hash (Hash) function.