Data Type - Abstract (ADT)
About
An abstract data type (ADT) is is defined by its methods (semantics) from the point of view of the user, specifically in terms of:
- possible values,
- possible operations.
It implements the concept of abstraction.
An ADT may have then several implementation. (And therefore several concrete representations on the disk).
An ADT is implemented in a language through an interface. The two terms are then interchangeable.
All type that are not abstract are called concrete types.
Articles Related
Example
The Abstract Data Type table may be implemented as:
- a list of row
- or a list of column
Add the fact that data may be compressed and you may have aliases in one of this list.