A dictionary (also known as map, associative array, or symbol table) in computer science is a data structure that maps keys to values such that given a key its corresponding value can be efficiently retrieved.
It is commonly implemented as a hash map which allow
O(1) amortized lookup. Alternatively, they may be implemented as a sorted list, with lookup requiring a binary search and making the lookup
O(log N) amortized instead.
When tagging a question with dictionary, be sure to tag it with the language being used as well.
std::map<Key, T, Compare, Allocator>: A sorted associative container that contains key-value pairs with unique keys.
Dictionary<TKey, TValue>: Represents a collection of keys and values.
dict: Maps hashable keys to arbitrary objects.
Map<K, V>: An object that maps keys to values.
Related tags: associative-array, unordered-map, multimap, treemap, hashmap, hashtable, lua-table
For questions about Mapping Functions over collections of data, use map-function tag.
For questions about the Geographical maps i.e. for visual representation of area, please use maps tag