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Hash Table

Also Known As Hash Map
Data Structure

A hash table is a data structure that implements an associative array, also called a dictionary or map: it stores key and value pairs and finds a value from its key in roughly constant expected time by computing where the entry lives rather than searching for it. The idea of hashing with chaining appears as early as January 1953, in an internal IBM memorandum by Hans Peter Luhn, and hash tables now sit inside nearly every language runtime and database. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/

Facts
Origin Year
1953 1
The January 1953 IBM memorandum by Hans Peter Luhn that used hashing with chaining.
Core Principle
Compute where a value belongs from its own key, so a lookup goes straight to the right place instead of searching. 1
Connections

Associated With

In Field

Sources
1. Wikipedia: Hash Table
Wikimedia Foundation
  • Overview and History sections
    a hash table is a data structure that implements an associative array, also called a dictionary or simply map
  • History section
    In January 1953, Hans Peter Luhn wrote an internal IBM memorandum that used hashing with chaining.
  • Introduction
    A hash table uses a hash function to compute an index, also called a hash code, into an array of buckets or slots, from which the desired value can be found.
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