Delegation (object-oriented Programming)
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Delegation (object-oriented Programming)
In object-oriented programming, delegation refers to evaluating a member (property or method) of one object (the receiver) in the context of another original object (the sender). Delegation can be done explicitly, by passing the sending object to the receiving object, which can be done in any object-oriented language; or implicitly, by the member lookup rules of the language, which requires language support for the feature. Implicit delegation is the fundamental method for behavior reuse in prototype-based programming, corresponding to inheritance in class-based programming. The best-known languages that support delegation at the language level are Self, which incorporates the notion of delegation through its notion of mutable parent slots that are used upon method lookup on self calls, and JavaScript; see JavaScript delegation. The term ''delegation'' is also used loosely for various other relationships between objects; see delegation (programming) for more. Frequently confused ...
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Object-oriented Programming
Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of procedures (often known as ''methods''). A common feature of objects is that procedures (or methods) are attached to them and can access and modify the object's data fields. In this brand of OOP, there is usually a special name such as or used to refer to the current object. In OOP, computer programs are designed by making them out of objects that interact with one another. OOP languages are diverse, but the most popular ones are class-based, meaning that objects are instances of classes, which also determine their types. Many of the most widely used programming languages (such as C++, Java, Python, etc.) are multi-paradigm and they support object-oriented programming to a greater or lesser degree, typically in combination with imper ...
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Aspect-oriented Programming
In computing, aspect-oriented programming (AOP) is a programming paradigm that aims to increase modularity by allowing the separation of cross-cutting concerns. It does so by adding behavior to existing code (an advice) ''without'' modifying the code itself, instead separately specifying which code is modified via a "pointcut" specification, such as "log all function calls when the function's name begins with 'set. This allows behaviors that are not central to the business logic (such as logging) to be added to a program without cluttering the code core to the functionality. AOP includes programming methods and tools that support the modularization of concerns at the level of the source code, while aspect-oriented software development refers to a whole engineering discipline. Aspect-oriented programming entails breaking down program logic into distinct parts (so-called ''concerns'', cohesive areas of functionality). Nearly all programming paradigms support some level of groupi ...
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Aggregation (object-oriented Programming)
In computer science, object composition and object aggregation are closely related ways to combine objects or data types into more complex ones. In conversation the distinction between composition and aggregation is often ignored. Common kinds of compositions are objects used in object-oriented programming, tagged unions, sets, sequences, and various graph structures. Object compositions relate to, but are not the same as, data structures. Object composition refers to the logical or conceptual structure of the information, not the implementation or physical data structure used to represent it. For example, a sequence differs from a set because (among other things) the order of the composed items matters for the former but not the latter. Data structures such as arrays, linked lists, hash tables, and many others can be used to implement either of them. Perhaps confusingly, some of the same terms are used for both data structures and composites. For example, " binary tre ...
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Role-oriented Programming
Role-oriented programming as a form of computer programming aims at expressing things in terms that are analogous to human conceptual understanding of the world. This should make programs easier to understand and maintain. The main idea of role-oriented programming is that humans think in terms of roles. This claim is often backed up by examples of social relations. For example, a student attending a class and the same student at a party are the same person, yet that person plays two different roles. In particular, the interactions of this person with the outside world depend on his current role. The roles typically share features, e.g., the intrinsic properties of being a person. This sharing of properties is often handled by the delegation mechanism. In the older literature and in the field of databases, it seems that there has been little consideration for the context in which roles interplay with each other. Such a context is being established in newer role- and aspect-ori ...
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Object Schizophrenia
Object schizophrenia or self schizophrenia is a complication arising from delegation and related techniques in object-oriented programming, where self/this can refer to more than one object. By way of metaphor with the public confusion of dissociative identity disorder with the psychiatric diagnosis of schizophrenia, the former being associated with "split personalities," this configuration is called ''object schizophrenia'' or ''self schizophrenia'' in object-oriented programming. Overview An object can be defined as a computing concept combining data and behavior, and having an identity. In class-based programming, objects are built on class systems, where an object is an instance of a class. Classes can in turn be related by inheritance: a ''base class'' provides the fundamental or default behavior of an object, and acts as a template for creating objects, while a ''derived class'' can be used to override behaviors of a base class, and can be used as a template for objects whos ...
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Java (programming Language)
Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers ''write once, run anywhere'' ( WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but has fewer low-level facilities than either of them. The Java runtime provides dynamic capabilities (such as reflection and runtime code modification) that are typically not available in traditional compiled languages. , Java was one of the most popular programming languages in use according to GitHub, particularly for client–server web applications, with a reported 9 million developers. Java was originally developed ...
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C Sharp (programming Language)
C# (pronounced ) is a general-purpose, high-level multi-paradigm programming language. C# encompasses static typing, strong typing, lexically scoped, imperative, declarative, functional, generic, object-oriented (class-based), and component-oriented programming disciplines. The C# programming language was designed by Anders Hejlsberg from Microsoft in 2000 and was later approved as an international standard by Ecma (ECMA-334) in 2002 and ISO/IEC (ISO/IEC 23270) in 2003. Microsoft introduced C# along with .NET Framework and Visual Studio, both of which were closed-source. At the time, Microsoft had no open-source products. Four years later, in 2004, a free and open-source project called Mono began, providing a cross-platform compiler and runtime environment for the C# programming language. A decade later, Microsoft released Visual Studio Code (code editor), Roslyn (compiler), and the unified .NET platform (software framework), all of which support C# and are free, open ...
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Pseudocode
In computer science, pseudocode is a plain language description of the steps in an algorithm or another system. Pseudocode often uses structural conventions of a normal programming language, but is intended for human reading rather than machine reading. It typically omits details that are essential for machine understanding of the algorithm, such as variable declarations and language-specific code. The programming language is augmented with natural language description details, where convenient, or with compact mathematical notation. The purpose of using pseudocode is that it is easier for people to understand than conventional programming language code, and that it is an efficient and environment-independent description of the key principles of an algorithm. It is commonly used in textbooks and scientific publications to document algorithms and in planning of software and other algorithms. No broad standard for pseudocode syntax exists, as a program in pseudocode is not an executa ...
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Trygve Reenskaug
Trygve Mikkjel Heyerdahl Reenskaug (born 21 June 1930) is a Norwegian computer scientist and professor emeritus of the University of Oslo. He formulated the model–view–controller (MVC) pattern for graphical user interface (GUI) software design in 1979 while visiting the Xerox Palo Alto Research Center (PARC). His first major software project, "Autokon," produced a successful computer-aided design – computer-aided manufacturing (CAD/CAM) program which was first used in 1963, and continued in use by shipyards worldwide for more than 30 years. Reenskaug described his early Smalltalk and object-oriented programming conceptual efforts as follows: He has been extensively involved in research into object-oriented methods and developed the Object Oriented Role Analysis and Modeling (OOram) and the OOram tool in 1983. He founded the information technology company Taskon in 1986, which developed tools based on OOram. The OOram ideas matured and evolved substantially into the BabyU ...
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Forwarding (object-oriented Programming)
In object-oriented programming, forwarding means that using a member of an object (either a property or a method) results in actually using the corresponding member of a different object: the use is ''forwarded'' to another object. Forwarding is used in a number of design patterns, where some members are forwarded to another object, while others are handled by the directly used object. The forwarding object is frequently called a wrapper object, and explicit forwarding members are called wrapper functions. Delegation Forwarding is often confused with delegation; formally, they are complementary concepts. In both cases, there are two objects, and the first (sending, wrapper) object uses the second (receiving, wrappee) object, for example to call a method. They differ in what self refers to on the receiving object (formally, in the evaluation environment of the method on the receiving object): in delegation it refers to the sending object, while in forwarding it refers to the receiv ...
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NeXTStep
NeXTSTEP is a discontinued object-oriented, multitasking operating system based on the Mach kernel and the UNIX-derived BSD. It was developed by NeXT Computer in the late 1980s and early 1990s and was initially used for its range of proprietary workstation computers such as the NeXTcube. It was later ported to several other computer architectures. Although relatively unsuccessful at the time, it attracted interest from computer scientists and researchers. It hosted the original development of the Electronic AppWrapper, the first commercial electronic software distribution catalog to collectively manage encryption and provide digital rights for application software and digital media, a forerunner of the modern "app store" concept. It is the platform on which Tim Berners-Lee created the first web browser, and on which id Software developed the video games ''Doom'' and '' Quake''. In 1996, NeXT was acquired by Apple Computer to succeed the classic Mac OS, by merging NeXTSTEP ...
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