Understanding the Abstract Data Type (ADT)
In Computer Science, an Abstract Data Type (ADT) is a mathematical model for data types where the type is defined by its behavior (semantics) from the point of view of a user of the data. This definition specifically focuses on what operations can be performed and what the results of those operations are, rather than how those operations are implemented in Memory. This separation of concerns is a cornerstone of Software Engineering and Object-Oriented Programming.
Principles of Abstraction
The primary goal of an ADT is Abstraction. By utilizing an Interface, a programmer can hide the underlying Data Structure and Implementation details. For instance, a Stack ADT defines operations such as push and pop. Whether that Stack is implemented using an Array or a Linked List is irrelevant to the user of the ADT. This concept is closely related to Encapsulation and Information Hiding. Detailed theoretical frameworks for ADTs were pioneered by researchers like Barbara Liskov in the 1970s.
Common Examples of ADTs
Many fundamental structures in programming are treated as ADTs before they are coded. Examples include the Queue, Priority Queue, Set, Map (also known as a Dictionary), and Graph. Each of these provides a specific set of rules for data access and manipulation. External academic resources such as Wikipedia and GeeksforGeeks provide extensive documentation on the formal specifications of these types.