data abstraction

Englisch - Englisch

Definition von data abstraction im Englisch Englisch wörterbuch: the idea of defining a data representation (for example, to represent a calendar date), and a set of operations to manipulate that representation, with no public access to the representation except via the operations See class; User defined types that abstract away the details of the data stored so that the data type can be treated as a whole; The object programming principle whereby a general description of an entire class of objects is defined instead of defining each object individually Information such as the type of data stored in the object and the type and form of the services (methods) that the class provides would be included in the type definition Concrete objects can then be created using the data type abstractions Data type abstractions are implemented in C++ through class or structure definitions; A data abstraction is a genus or community It can be thought of as a set of species or families But it can also be thought of in terms of the capabilities that it represents For example, genus ORDER contains species that support order tests (<, etc ) See T5, T14, T16 and T17; Data abstraction is what keeps the caller of a procedure from accessing data that the procedure manipulates Algol60's own variables provided a special form of this Private instance variables in OO languages provide a more general form; the separation of the logical properties or operations on data from the implementation of the data and operations; A style of programming in which you define types to represent objects in your program, define a set of operations for objects of each type, and restrict the operations to only this set, making the types abstract The Fortran 95/90 modules, derived types, and defined operators, support this programming paradigm; The grouping of a complex set of data items into a single unit, such as a data type represented by an array or record; One of the four principles of object orientation Data abstraction is the process by which a particular data structure is viewed as representing an abstraction For example, a pair of floats may represent an interval on the real line Once this abstraction is identified, the particular data structure is replaced by access routines which define the abstraction Any data structure that provides the same access routines (and which behaves in a manner consistant with whatever assumptions made by the abstraction) may replace the original data structure, without requiring modifications of code which manipulates the data structure; Programming paradigm including modularity The essential characteristic of an object that distinguish it from all other kinds of objects and thus provide crisply defined conceptual boundaries, relative to the perspective of the viewer Characteristic of the Object Design Model