|
Composition (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 tree" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Science
Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, applied disciplines (including the design and implementation of Computer architecture, hardware and Software engineering, software). Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of computational problem, problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and preventing security vulnerabilities. Computer graphics (computer science), Computer graphics and computational geometry address the generation of images. Programming language theory considers different ways to describe computational processes, and database theory concerns the management of re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interface (object-oriented Programming)
In object-oriented programming, an interface or protocol type is a data type that acts as an abstraction of a Class (computer science), class. It describes a set of method signatures, the implementations of which may be provided by multiple class (computer programming), classes that are otherwise not necessarily related to each other. A class which provides the methods listed in an interface is said to ''implement'' the interface, or to ''adopt'' the protocol. Examples If objects are fully encapsulation (object-oriented programming), encapsulated then the interface is the only way in which they may be accessed by other objects. For example, in Java (programming language), Java, the Comparable interface specifies a method compareTo() which implementing classes must implement. This means that a sorting method, for example, can sort a collection of any objects of types which implement the Comparable interface, without having to know anything about the inner nature of the class (excep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Type
In computer science, a composite data type or compound data type is a data type that consists of programming language scalar data types and other composite types that may be heterogeneous and hierarchical in nature. It is sometimes called a structure or a record or by a language-specific keyword used to define one such as struct. It falls into the aggregate type classification which includes homogenous collections such as the array and list A list is a Set (mathematics), set of discrete items of information collected and set forth in some format for utility, entertainment, or other purposes. A list may be memorialized in any number of ways, including existing only in the mind of t .... See also * * * * References {{Data types Data types Type theory Articles with example C code Articles with example C++ code ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field (computer Science)
In data hierarchy, a field (data field) is a Variable (computer science), variable in a record (computer science), record. A record, also known as a data structure, allows logically related data to be identified by a single name. Identifying related data as a single group is central to the construction of understandable computer programs. The individual fields in a record may be accessed by name, just like any variable in a computer program. Each field in a record has two components. One component is the field's data type, datatype Declaration (computer programming), declaration. The other component is the field's identifier. Memory fields Fields may be stored in random access memory (RAM). The following Pascal (programming language), Pascal record definition has three field identifiers: firstName, lastName, and age. The two name fields have a datatype of an Array (data structure), array of Character (computing), character. The age field has a datatype of integer. type PersonRec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JavaScript
JavaScript (), often abbreviated as JS, is a programming language and core technology of the World Wide Web, alongside HTML and CSS. Ninety-nine percent of websites use JavaScript on the client side for webpage behavior. Web browsers have a dedicated JavaScript engine that executes the client code. These engines are also utilized in some servers and a variety of apps. The most popular runtime system for non-browser usage is Node.js. JavaScript is a high-level, often just-in-time–compiled language that conforms to the ECMAScript standard. It has dynamic typing, prototype-based object-orientation, and first-class functions. It is multi-paradigm, supporting event-driven, functional, and imperative programming styles. It has application programming interfaces (APIs) for working with text, dates, regular expressions, standard data structures, and the Document Object Model (DOM). The ECMAScript standard does not include any input/output (I/O), such as netwo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prototype-based Programming
Prototype-based programming is a style of object-oriented programming in which behavior reuse (known as inheritance) is performed via a process of reusing existing objects that serve as prototypes. This model can also be known as ''prototypal'', ''prototype-oriented,'' ''classless'', or ''instance-based'' programming. Prototype-based programming uses the process generalized objects, which can then be cloned and extended. Using fruit as an example, a "fruit" object would represent the properties and functionality of fruit in general. A "banana" object would be cloned from the "fruit" object and general properties specific to bananas would be appended. Each individual "banana" object would be cloned from the generic "banana" object. Compare to the class-based paradigm, where a "fruit" ''class'' would be extended by a "banana" ''class''. History The first prototype-based programming languages were Director a.k.a. Ani (on top of MacLisp) (1976-1979), and contemporaneously and no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ontology
Ontology is the philosophical study of existence, being. It is traditionally understood as the subdiscipline of metaphysics focused on the most general features of reality. As one of the most fundamental concepts, being encompasses all of reality and every entity within it. To articulate the basic structure of being, ontology examines the commonalities among all things and investigates their classification into basic types, such as the Theory of categories, categories of particulars and Universal (metaphysics), universals. Particulars are unique, non-repeatable entities, such as the person Socrates, whereas universals are general, repeatable entities, like the color ''green''. Another distinction exists between Abstract and concrete, concrete objects existing in space and time, such as a tree, and abstract objects existing outside space and time, like the number 7. Systems of categories aim to provide a comprehensive inventory of reality by employing categories such as Substance t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Is-a
In knowledge representation, ontology components and ontology engineering, including for object-oriented programming and design, is-a (also written as is_a or is a) is a subsumptive relationship between abstractions (e.g., types, classes), wherein one class ''A'' is a subclass of another class ''B'' (and so ''B'' is a superclass of ''A''). In other words, type A is a subtype of type B when A's specification implies B's specification. That is, any object (or class) that satisfies A's specification also satisfies B's specification, because B's specification is weaker. For example, a cat 'is a animal, but not vice versa. All cats are animals, but not all animals are cats. Behaviour that is relevant to all animals is defined on an animal class, whereas behaviour that is relevant only for cats is defined in a cat class. By defining the cat class as 'extending' the animal class, all cats 'inherit' the behaviour defined for animals, without the need to explicitly code that behavi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subtyping
In programming language theory, subtyping (also called subtype polymorphism or inclusion polymorphism) is a form of type polymorphism. A ''subtype'' is a datatype that is related to another datatype (the ''supertype'') by some notion of substitutability, meaning that program elements (typically subroutines or functions), written to operate on elements of the supertype, can also operate on elements of the subtype. If S is a subtype of T, the subtyping relation (written as , , or ) means that any term of type S can ''safely be used'' in ''any context'' where a term of type T is expected. The precise semantics of subtyping here crucially depends on the particulars of how ''"safely be used"'' and ''"any context"'' are defined by a given type formalism or programming language. The type system of a programming language essentially defines its own subtyping relation, which may well be trivial, should the language support no (or very little) conversion mechanisms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mereology
Mereology (; from Greek μέρος 'part' (root: μερε-, ''mere-'') and the suffix ''-logy'', 'study, discussion, science') is the philosophical study of part-whole relationships, also called ''parthood relationships''. As a branch of metaphysics, mereology examines the connections between parts and their wholes, exploring how components interact within a system. This theory has roots in ancient philosophy, with significant contributions from Plato, Aristotle, and later, medieval and Renaissance thinkers like Thomas Aquinas and John Duns Scotus. Mereology was formally axiomatized in the 20th century by Polish logician Stanisław Leśniewski, who introduced it as part of a comprehensive framework for logic and mathematics, and coined the word "mereology". Mereological ideas were influential in early , and formal mereology has continued to be used by a minority in works on the . Different axiomatizations of mereology have been applied in , used in to analyze "mass terms", use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Role
A role (also rôle or social role) is a set of connected behaviors, rights, obligations, beliefs, and norms as conceptualized by people in a social situation. It is an expected or free or continuously changing behavior and may have a given individual social status or social position. It is vital to both functionalist and interactionist understandings of society. Social role theory posits the following about social behavior: # The division of labour in society takes the form of the interaction among heterogeneous specialized positions, we call roles. # Social roles included appropriate and permitted forms of behavior and actions that recur in a group, guided by social norms, which are commonly known and hence determine the expectations for appropriate behavior in these roles, which further explains the position of a person in the society. # Roles are occupied by individuals, who are called actors. #When individuals approve of a social role (i.e., they consider the role legit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Has-a
In database design, object-oriented programming and Object-oriented design, design, has-a (has_a or has a) is a Object composition, composition relationship where one object (often called the constituted object, or part/constituent/member object) "belongs to" (is object composition, part or member of) another object (called the composite type), and behaves according to the rules of ownership. In simple words, has-a relationship in an object is called a member field of an object. Multiple has-a relationships will combine to form a possessive hierarchy. Related concepts "Has-a" is to be contrasted with an ''is-a'' (''is_a'' or ''is a'') relationship which constitutes a taxonomic hierarchy (subtyping). The decision whether the most logical relationship for an object and its subordinate is not always clearly ''has-a'' or ''is-a''. Confusion over such decisions have necessitated the creation of these metalinguistic terms. A good example of the ''has-a'' relationship is containers in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
