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Has-a
In database design, object-oriented programming and design (see object oriented program architecture), has-a (has_a or has a) is a composition relationship where one object (often called the constituted object, or part/constituent/member object) "belongs to" (is 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. This 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 the C++ STL. To summarize the relatio ... [...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] |
Is-a
In knowledge representation, object-oriented programming and design (see object-oriented program architecture), is-a (is_a or is a) is a subsumption 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. The ''is-a'' relationship is to be contrasted with the '' has-a'' (''has_a'' or ''has a'') relationship between types (classes); confusing the relations ''has-a'' and ''is-a'' is a common error when designing a model (e.g., a computer program) of the real-world relationship between an object and its subordinate. The ''is-a'' relationship may also be contrasted with the '' instance-of'' relationship between objects (instances) and types (classes) ... [...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] |
Is-a
In knowledge representation, object-oriented programming and design (see object-oriented program architecture), is-a (is_a or is a) is a subsumption 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. The ''is-a'' relationship is to be contrasted with the '' has-a'' (''has_a'' or ''has a'') relationship between types (classes); confusing the relations ''has-a'' and ''is-a'' is a common error when designing a model (e.g., a computer program) of the real-world relationship between an object and its subordinate. The ''is-a'' relationship may also be contrasted with the '' instance-of'' relationship between objects (instances) and types (classes) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object Oriented
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inheritance (object-oriented Programming)
In object-oriented programming, inheritance is the mechanism of basing an object or class upon another object ( prototype-based inheritance) or class ( class-based inheritance), retaining similar implementation. Also defined as deriving new classes ( sub classes) from existing ones such as super class or base class and then forming them into a hierarchy of classes. In most class-based object-oriented languages, an object created through inheritance, a "child object", acquires all the properties and behaviors of the "parent object" , with the exception of: constructors, destructor, overloaded operators and friend functions of the base class. Inheritance allows programmers to create classes that are built upon existing classes, to specify a new implementation while maintaining the same behaviors ( realizing an interface), to reuse code and to independently extend original software via public classes and interfaces. The relationships of objects or classes through inheritance give ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meronymy
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. 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 hyponym which refers to ''type''. For example, a holonym of ''leaf'' might be ''tree'' (a leaf is a part of a tree), whereas a hyponym of ''oak tree'' might be ''tree'' (an oak tree is a type of tree). See also * Has-a * Hyponymy and hypernymy * Is-a * Mereological nihilism * Synec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instance (computer Science)
In a computer system, any time a new context is created based on some model, it is said that the model has been instantiated. In practice, this instance usually has a data structure in common with other instances, but the values stored in the instances are separate. Changing the values in one instance will then not interfere with the values of some other instance. A compute instance can be software or hardware which can run code, for example a CPU, GPU or a virtual machine. Computer graphics In computer graphics, a polygonal model can be instantiated in order to be drawn several times in different locations in a scene. This is a technique that can be used to improve the performance of rendering, since the work needed to display each instance overlaps. Object-oriented programming In object-oriented programming (OOP), an instance is a concrete occurrence of any object, existing usually during the runtime of a computer program. Formally, "instance" is synonymous with "object ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
