Object-Oriented Paradigm

In this chapter, we discuss object-oriented languages. We attempt to present the linguistic aspects which concern objects and their use, starting with a presentation of objects as a way to gain data abstraction in a way that is both flexible and extensible. This will lead us to describe the concepts of objects and classes, and, then, those of encapsulation, subtypes (that is a compatibility relation based on the functionality of an object), inheritance (that is the possibility of reusing the implementation of a method previously defined in another object or for another class), and dynamic method selection. Having examined these characteristic aspects in detail, we will study some extensions to linguistic solutions that are available in commercial languages, referring, in particular, to the concepts of subtype, polymorphism and genericity.