File:Hash_table_3_1_1_0_1_0_0_SP.svg · Wikimedia Commons · See Wikimedia Commons
hash table
Sign in to saveAlso known as hash map, hashtable, hashmap
associates data values with key values - a lookup table
Key facts
- Type
- Unordered associative array
- Operation
- Average
- Search
- Θ(1)
- Insert
- Θ(1)
- Delete
- Θ(1)
- Space
- Θ( n )
via Wikipedia infobox
Wikidata facts
- Image
- HASHTB12.svg
Show 4 more facts
- Commons category
- Hash tables
- inception
- 1953-00-00
- time of discovery or invention
- 1953-00-00
- Stack Exchange tag
- stackoverflow.com/tags/hashmap
via Wikidata · CC0
~29 min read
Article
A small phone book as a hash table
In computer science, a hash table is a data structure that implements an associative array, also called a dictionary or simply map; an associative array is an abstract data type that maps keys to values. 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. During lookup, the key is hashed and the resulting hash indicates where the corresponding value is stored. A map implemented by a hash table is called a hash map.