Object-Oriented Programming Versus Abstract Data Types

This tutorial collects and elaborates arguments for distinguishing between object-oriented programming and abstract data types. The basic distinction is that object-oriented programming achieves data abstraction by the use of procedural abstraction, while abstract data types depend upon type abstraction. Object-oriented programming and abstract data types can also be viewed as complimentary implementation techniques: objects are centered around the constructors of a data abstraction, while abstract data types are organized around the operations. These differences have consequences relating to extensibility, efficiency, typing, and verification; in many cases the strengths of one paradigm are the weaknesses of the other. Most object-oriented programming languages support aspects of both techniques, not a unification of them, so an understanding of their relative merits is useful in designing programs. Published in the Proceedings of the REX Workshop/School on the Foundations of Object-Oriented Languages, LNCS 173, Springer-Verlag, 1990, pp. 151-178.