(Collection|Container) Data Type (Set, Bag, Sequence)

A collection is a abstract data type for grouping together multiple values.

It's therefore sometime known as a container and creates a aggregation relationship

A collection is:

• an object that groups multiple elements into a single unit.
• just a grouping of some objects with the same type.

Once the data has been put in a collection, the data has been aggregated and we get aggregate data

Collections are used to store, retrieve, manipulate, and communicate aggregate data.

The inverse of a collection (ie a single element) is called a scalar.

An array is a collection structure that is used to implement [#abstract|abstract collection]].

The Primary abstract data type are base on this two properties:

• ordering mater: Ie (A,B) is not the same than (B,A)
• unique: allow or not duplicate

Collection that can be seen as a set

• A tree is a collection of a collection. <note tip>Most of the collection are implemented via a tree structure to permit a fast access</note>
• A queue or stack is a sequence where the extraction of elements is determined by the notion of first or last
• A graph is set of node and a set of edge.
• A string is a sequence of character

Standard Operations on collection are defined in functional programming

• Collection_(abstract_data_type)