Set

Set is a data structure commonly used in computer programming. It is an unordered collection of data, meaning that it is not stored in a particular order. It is distinct from lists, which are ordered collections of data, and maps, which are collections of data consisting of key-value pairs.

Sets are most commonly used in functional programming, where they can be used to represent finite or potentially infinite sets of values. They may also be used in imperative programming and object-oriented programming.

Depending on the language they are implemented in, sets may offer different methods of modification, such as adding new elements and removing existing elements. In some languages, it may be possible to construct sets from lists, and vice versa.

Sets are widely used for tasks such as representing sets of keys (e.g. for a hash table or set of flags), finding the difference or intersection of sets, and; checking whether a value is in a set.

Set data structures can also be used to provide optimizations when computing certain mathematical functions, such as the union, intersection, and difference of two sets.

Sets may also be implemented as specialized data structures, such as a red-black tree or a balanced tree, in order to provide faster runtime for operations such as member testing or insertion.