< programming > A hash coding function which assigns a data item distinguished by some "key" into one of a number of possible "hash buckets" in a hash table. The hash function is usually combined with another more precise function.
For example a program might take a string of letters and put it in one of twenty six lists depending on its first letter. Ideally, a hash function should distribute items evenly between the buckets to reduce the number of hash collisions . If, for example, the strings were names beginning with "Mr.", "Miss" or "Mrs." then taking the first letter would be a very poor hash function because all names would hash the same.
(1997-08-03)