Object (computer science)

In software development, an object is an entity that has state, behavior, and identity.^[1]^: 78 An object can model some part of reality or can be an invention of the design process whose collaborations with other such objects serve as the mechanisms that provide some higher-level behavior. Put another way, an object represents an individual, identifiable item, unit, or entity, either real or abstract, with a well-defined role in the problem domain.^[1]^: 76

A programming language can be classified based on its support for objects. A language that provides an encapsulation construct for state, behavior, and identity is classified as object-based. If the language also provides polymorphism and inheritance it is classified as object-oriented. A language that supports creating an object from a class is classified as class-based. A language that supports object creation via a template object is classified as prototype-based.

The concept of object is used in many different software contexts, including:

Possibly the most common use is in-memory objects in a computer program written in an object-based language.

Information systems can be modeled with objects representing their components and interfaces.^[1]^: 39

In the relational model of database management, aspects such as table and column may act as objects.^[2]

Objects of a distributed computing system tend to be larger grained, longer lasting, and more service-oriented than programming objects.

References

^ ^a ^b ^c Grady Booch; Robert Maksimchuk; Michael Engle; Bobbi Young; Jim Conallen; Kelli Houston (April 30, 2007). Object-Oriented Analysis and Design with Applications (3 ed.). Addison-Wesley Professional. ISBN 020189551X.
^ Oppel, Andy (2005). SQL Demystified. McGraw Hill. p. 7. ISBN 0-07-226224-9.

External links

What Is an Object? from The Java Tutorials

[ooa-1] Grady Booch; Robert Maksimchuk; Michael Engle; Bobbi Young; Jim Conallen; Kelli Houston (April 30, 2007). Object-Oriented Analysis and Design with Applications (3 ed.). Addison-Wesley Professional. ISBN 020189551X.

[Oppel-2] Oppel, Andy (2005). SQL Demystified. McGraw Hill. p. 7. ISBN 0-07-226224-9.

[1]

[2]

v t e Data types
Uninterpreted	Bit Byte Trit Tryte Word Bit array
Numeric	Arbitrary-precision or bignum Complex Decimal Fixed point Floating point Reduced precision Minifloat Half precision bfloat16 Single precision Double precision Quadruple precision Octuple precision Extended precision Long double Integer signedness Interval Rational
Pointer	Address physical virtual Reference
Text	Character String null-terminated
Composite	Algebraic data type generalized Array Associative array Class Dependent Equality Inductive Intersection List Object metaobject Option type Product Record or Struct Refinement Set Union tagged
Other	Boolean Bottom type Collection Enumerated type Exception Function type Opaque data type Recursive data type Semaphore Stream Strongly typed identifier Top type Type class Empty type Unit type Void
Related topics	Abstract data type Boxing Data structure Generic Kind metaclass Parametric polymorphism Primitive data type Interface Subtyping Type constructor Type conversion Type system Type theory Variable

Object (computer science)

See also

References

External links