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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] |
Computer Program
A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. It is one component of software, which also includes software documentation, documentation and other intangible components. A ''computer program'' in its human-readable form is called source code. Source code needs another computer program to Execution (computing), execute because computers can only execute their native machine instructions. Therefore, source code may be Translator (computing), translated to machine instructions using a compiler written for the language. (Assembly language programs are translated using an Assembler (computing), assembler.) The resulting file is called an executable. Alternatively, source code may execute within an interpreter (computing), interpreter written for the language. If the executable is requested for execution, then the operating system Loader (computing), loads it into Random-access memory, memory and ... [...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] |
Typeof
typeof, alternately also typeOf, and TypeOf, is an operator provided by several programming languages to determine the data type of a variable. This is useful when constructing programs that must accept multiple types of data without explicitly specifying the type. In languages that support polymorphism and type casting, the typeof operator may have one of two distinct meanings when applied to an object. In some languages, such as Visual Basic, the typeof operator returns the dynamic type of the object. That is, it returns the true, original type of the object, irrespective of any type casting. In these languages, the typeof operator is the method for obtaining run-time type information. In other languages, such as C# or D and, to some degree, in C (as part of nonstandard extensions and proposed standard revisions),Typeof in "Using the GNU C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instance (computer Science)
In computer science, an instance is an occurrence of a software element that is based on a type definition. When created, an occurrence is said to have been ''instantiated'', and both the creation process and the result of creation are called ''instantiation''. Examples ; Class instance: An object-oriented programming (OOP) object created from a class. Each instance of a class shares a data layout but has its own memory allocation. ; Computer instance: An occurrence of a virtual machine which typically includes storage, a virtual CPU. ; Polygonal model: In computer graphics, it can be instantiated in order to be drawn several times in different locations in a scene which can improve the performance of rendering since a portion of the work needed to display each instance is reused. ; Program instance: In a POSIX-oriented operating system, it refers to an executing process A process is a series or set of activities that interact to produce a result; it may occur once-only o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Container (abstract Data Type)
In computer science, a container is a Class (computer science), class or a data structureEntry ''data structure'' in the Encyclopædia Britannica (2009Online entryAccessed 4 Oct 2011. whose instances are collections of other objects. In other words, they store objects in an organized way that follows specific access rules. The size of the container depends on the number of objects (elements) it contains. Underlying (inherited) implementations of various container types may vary in size, complexity and type of language, but in many cases they provide flexibility in choosing the right implementation for any given scenario. Container data structures are commonly used in many types of programming languages. Function and properties Containers can be characterized by the following three properties: * ''access'', that is the way of accessing the objects of the container. In the case of arrays, access is done with the array index. In the case of stacks, access is done according to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Containment (computer 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] |
Part-of
In linguistics, meronymy () is a semantic relation between a meronym denoting a part and a holonym denoting a whole. In simpler terms, a meronym is in a ''part-of'' relationship with its holonym. For example, ''finger'' is a meronym of ''hand,'' which is its holonym. Similarly, ''engine'' is a meronym of ''car,'' which is its holonym. Fellow meronyms (naming the various fellow parts of any particular whole) are called comeronyms (for example, ''leaves'', ''branches'', ''trunk'', and ''roots'' are comeronyms under the holonym of ''tree''). Holonymy () is the converse of meronymy. A closely related concept is that of mereology, which specifically deals with part–whole relations and is used in logic. It is formally expressed in terms of first-order logic. A meronymy can also be considered a partial order. Meronym and holonym refer to ''part'' and ''whole'' respectively, which is not to be confused with hypernym which refers to ''type''. For example, a holonym of ''leaf'' migh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Meronym
In linguistics, meronymy () is a semantic relation between a meronym denoting a part and a holonym denoting a whole. In simpler terms, a meronym is in a ''part-of'' relationship with its holonym. For example, ''finger'' is a meronym of ''hand,'' which is its holonym. Similarly, ''engine'' is a meronym of ''car,'' which is its holonym. Fellow meronyms (naming the various fellow parts of any particular whole) are called comeronyms (for example, ''leaves'', ''branches'', ''trunk'', and ''roots'' are comeronyms under the holonym of ''tree''). Holonymy () is the converse of meronymy. A closely related concept is that of mereology, which specifically deals with part–whole relations and is used in logic. It is formally expressed in terms of first-order logic. A meronymy can also be considered a partial order. Meronym and holonym refer to ''part'' and ''whole'' respectively, which is not to be confused with hypernym which refers to ''type''. For example, a holonym of ''leaf'' migh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
