Was (wer) ist abstract class - definition

FEATURE OF A PROGRAMMING LANGUAGE

Abstract class; Pure virtual class

abstract class

<programming> In object-oriented programming, a class designed only as a parent from which sub-classes may be derived, but which is not itself suitable for instantiation. Often used to "abstract out" incomplete sets of features which may then be shared by a group of sibling sub-classes which add different variations of the missing pieces. (1994-11-08)

Abstract type

In programming languages, an abstract type is a type in a nominative type system that cannot be instantiated directly; a type that is not abstract – which can be instantiated – is called a concrete type. Every instance of an abstract type is an instance of some concrete subtype.

https://en.wikipedia.org/wiki/Abstract_type

Abstract elementary class

CLASS OF MODELS WITH A PARTIAL ORDER SIMILAR TO THE RELATION OF AN ELEMENTARY SUBSTRUCTURE OF AN ELEMENTARY CLASS IN FIRST-ORDER MODEL THEORY

Abstract Elementary Class; Abstract elementary classes

In model theory, a discipline within mathematical logic, an abstract elementary class, or AEC for short, is a class of models with a partial order similar to the relation of an elementary substructure of an elementary class in first-order model theory. They were introduced by Saharon Shelah..

https://en.wikipedia.org/wiki/Abstract_elementary_class

Wikipedia

Abstract type

In programming languages, an abstract type is a type in a nominative type system that cannot be instantiated directly; a type that is not abstract – which can be instantiated – is called a concrete type. Every instance of an abstract type is an instance of some concrete subtype. Abstract types are also known as existential types.

An abstract type may provide no implementation, or an incomplete implementation. In some languages, abstract types with no implementation (rather than an incomplete implementation) are known as protocols, interfaces, signatures, or class types. 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 types may satisfy the same concept.

Often, abstract types will have one or more implementations provided separately, for example, in the form of concrete subtypes that can be instantiated. In object-oriented programming, an abstract class may include abstract methods or abstract properties that are shared by its subclasses. Other names for language features that are (or may be) used to implement abstract types include traits, mixins, flavors, roles, or type classes.

https://en.wikipedia.org/wiki/Abstract type