Search results
Results From The WOW.Com Content Network
In object-oriented programming theory, abstraction involves the facility to define objects that represent abstract "actors" that can perform work, report on and change their state, and "communicate" with other objects in the system.
In object oriented programming, objects provide a layer which can be used to separate internal from external code and implement abstraction and encapsulation. External code can only use an object by calling a specific instance method with a certain set of input parameters, reading an instance variable, or writing to an instance variable.
In class-based object-oriented programming, abstract types are implemented as abstract classes (also known as abstract base classes), and concrete types as concrete classes. In generic programming , the analogous notion is a concept , which similarly specifies syntax and semantics, but does not require a subtype relationship: two unrelated ...
All object-oriented programming (OOP) systems support encapsulation, [2] [3] but encapsulation is not unique to OOP. Implementations of abstract data types, modules, and libraries also offer encapsulation. The similarity has been explained by programming language theorists in terms of existential types. [4]
The abstraction principle is mentioned in several books. Some of these, together with the formulation if it is succinct, are listed below. Alfred John Cole, Ronald Morrison (1982) An introduction to programming with S-algol: "[Abstraction] when applied to language design is to define all the semantically meaningful syntactic categories in the language and allow an abstraction over them".
The C++ examples in this section demonstrate the principle of using composition and interfaces to achieve code reuse and polymorphism. Due to the C++ language not having a dedicated keyword to declare interfaces, the following C++ example uses inheritance from a pure abstract base class .
In object-oriented programming, an interface or protocol type [a] is a data type that acts as an abstraction of a class. It describes a set of method signatures, the implementations of which may be provided by multiple classes that are otherwise not necessarily related to each other. [1]
Modern object-oriented languages, such as C++ and Java, support a form of abstract data types. When a class is used as a type, it is an abstract type that refers to a hidden representation. When a class is used as a type, it is an abstract type that refers to a hidden representation.