散列表（Hash table，也叫哈希表），是根据关键码值(Key value)而直接进行访问的数据结构。也就是说，它通过把关键码值映射到表中一个位置来访问记录，以加快查找的速度。这个映射函数叫做散列函数，存放记录的数组叫做散列表。

给定表M，存在函数f(key)，对任意给定的关键字值key，代入函数后若能得到包含该关键字的记录在表中的地址，则称表M为哈希(Hash）表，函数f(key)为哈希(Hash) 函数。-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.