Associative array

In computing, an associative array, also known as a map, lookup table, or dictionary, is an abstract data type very closely related to the mathematical concept of a function with a finite domain. Conceptually, an associative array is composed of a collection of keys and a collection of values, and each key is associated with one value. The operation of finding the value associated with a key is called a lookup or indexing, and this is the most important operation supported by an associative array. The relationship between a key and its value is sometimes called a mapping or binding. For example, if the value associated with the key "bob" is 7, we say that our array maps "bob" to 7.

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From the perspective of a programmer using an associative array, it can be viewed as a generalization of an array: While a regular array maps integers to arbitrarily typed objects (integers, strings, pointers, and, in an OO sense, objects), an associative array maps arbitrarily typed objects to arbitrarily typed objects. (Implementations of the two data structures, though, may be considerably different.)

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The operations that are usually defined for an associative array are:

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• Add: Bind a new key to a new value
• Reassign: Bind an old key to a new value
• Remove: Unbind a key from a value and remove it from the key set
• Lookup: Find the value (if any) that is bound to a key
Associative array: Examples ►



 

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Associative array related Images and Photos (experimental)

Orchid Array I	Orchid Array III	An array of colored sea glass	Array of Electric Power Meters at a Boat Dock
Rendering of the Atacama Array	The Hubble Space Telescope reveals an array of galaxies	Thirty-Four Insects Laid Out in a Semi-Circular Array Mostly of the Order Coleoptera (Beetle)