hash function

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hash function

(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.

hash function

An algorithm that turns a variable amount of text into a small, fixed-length value called a "hash value," "hash code" or "digest." Hash functions are widely used to create codes for digital signatures and message authentication (see cryptographic hash function). Hash functions are also employed to create lookup tables (see hash table) as well as spam analysis (see hash buster).