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Helper Class
In object-oriented programming, a helper class is used to assist in providing some functionality, which isn't the main goal of the application or class in which it is used. An instance of a helper class is called a helper object (for example, in the delegation pattern). Helper classes are often created in introductory programming lessons, after the novice programmer has moved beyond creating one or two classes. A utility class is a special case of a helper class in which the methods are all static. In general, helper classes do not have to have all static methods, but may have instance variables. Multiple instances of the helper class may exist as well. Example This is also an example of a utility class. Below are extension methods on the string object. public static class PrependHelper Alternative to helper class Functions which are going to be helper classes could be placed close to where they are used. The other alternative is wrapping helper class parameters into a ... [...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''. Objects can contain data (called fields, attributes or properties) and have actions they can perform (called procedures or methods and implemented in code). In OOP, computer programs are designed by making them out of objects that interact with one another. Many of the most widely used programming languages (such as C++, Java, and Python) support object-oriented programming to a greater or lesser degree, typically as part of multiple paradigms in combination with others such as imperative programming and declarative programming. Significant object-oriented languages include Ada, ActionScript, C++, Common Lisp, C#, Dart, Eiffel, Fortran 2003, Haxe, Java, JavaScript, Kotlin, Logo, MATLAB, Objective-C, Object Pascal, Perl, PHP, Python, R, Raku, Ruby, Scala, SIMSCRIPT, Simula, Smalltalk, Swift, Vala and Visual Basic.NET. History The idea of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delegation Pattern
In software engineering, the delegation pattern is an object-oriented design pattern that allows object composition to achieve the same code reuse as inheritance. In delegation, an object handles a request by delegating to a second object (the ''delegate''). The delegate is a helper object, but ''with the original context''. With language-level support for delegation, this is done implicitly by having self in the delegate refer to the original (sending) object, not the delegate (receiving object). In the delegate pattern, this is instead accomplished by explicitly passing the original object to the delegate, as an argument to a method. "Delegation" is often used loosely to refer to the distinct concept of forwarding, where the sending object simply uses the corresponding member on the receiving object, evaluated in the context of the ''receiving'' object, not the original object. This article uses "sending object/receiving object" for the two objects, rather than "receiving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utility Class
In economics, utility is a measure of a certain person's satisfaction from a certain state of the world. Over time, the term has been used with at least two meanings. * In a normative context, utility refers to a goal or objective that we wish to maximize, i.e., an objective function. This kind of utility bears a closer resemblance to the original utilitarian concept, developed by moral philosophers such as Jeremy Bentham and John Stuart Mill. * In a descriptive context, the term refers to an ''apparent'' objective function; such a function is revealed by a person's behavior, and specifically by their preferences over lotteries, which can be any quantified choice. The relationship between these two kinds of utility functions has been a source of controversy among both economists and ethicists, with most maintaining that the two are distinct but generally related. Utility function Consider a set of alternatives among which a person has a preference ordering. A utility functi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extension Method
In object-oriented computer programming, an extension method is a method added to an object after the original object was compiled. The modified object is often a class, a prototype, or a type. Extension methods are features of some object-oriented programming languages. There is no syntactic difference between calling an extension method and calling a method declared in the type definition. Not all languages implement extension methods in an equally safe manner, however. For instance, languages such as C#, Java (viManifold d > 3).Select(d => Math.Sin(d / 2)).Sum()); // Output: // 1 Centralize common behavior However, extension methods allow features to be implemented once in ways that enable reuse without the need for inheritance or the overhead of virtual method invocations, or to require implementors of an interface to implement either trivial or woefully complex functionality. A particularly useful scenario is if the feature operates on an interface for which there i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hierarchy (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 like C++, an object created through inheritance, a "child object", acquires all the properties and behaviors of the "parent object", with the exception of: constructors, destructors, 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 inheri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class Diagram
In software engineering, a class diagram in the Unified Modeling Language (UML) is a type of static structure diagram that describes the structure of a system by showing the system's classes, their attributes, operations (or methods), and the relationships among objects. The class diagram is the main building block of object-oriented modeling. It is used for general conceptual modeling of the structure of the application, and for detailed modeling, translating the models into programming code. Class diagrams can also be used for data modeling Data modeling in software engineering is the process of creating a data model for an information system by applying certain formal techniques. It may be applied as part of broader Model-driven engineering (MDE) concept. Overview Data modeli .... The classes in a class diagram represent both the main elements, interactions in the application, and the classes to be programmed. In the diagram, classes are represented with boxes that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class-based Programming
Class-based programming, or more commonly class-orientation, is a style of object-oriented programming (OOP) in which inheritance (object-oriented programming), inheritance occurs via defining ''class (computer programming), classes'' of object (computer science), objects, instead of inheritance occurring via the objects alone (compare prototype-based programming). The most popular and developed model of OOP is a class-based model, instead of an object-based model. In this model, objects are entities that combine ''state (computer science), state'' (i.e., data), ''behavior'' (i.e., procedures, or ''method (computer science), methods'') and ''identity (object-oriented programming), identity'' (unique existence among all other objects). The structure and behavior of an object are defined by a class (object-oriented programming), class, which is a definition, or blueprint, of all objects of a specific type. An object must be explicitly created based on a class and an object thus crea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
