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Contexts And Dependency Injection
In software engineering, dependency injection is a programming technique in which an object or function receives other objects or functions that it requires, as opposed to creating them internally. Dependency injection aims to separate the concerns of constructing objects and using them, leading to loosely coupled programs. The pattern ensures that an object or function that wants to use a given service should not have to know how to construct those services. Instead, the receiving "client" (object or function) is provided with its dependencies by external code (an "injector"), which it is not aware of. Dependency injection makes implicit dependencies explicit and helps solve the following problems: * How can a class be independent from the creation of the objects it depends on? * How can an application, and the objects it uses support different configurations? Dependency injection is often used to keep code in-line with the dependency inversion principle. In statically typed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Application Programming Interface
An application programming interface (API) is a connection between computers or between computer programs. It is a type of software Interface (computing), interface, offering a service to other pieces of software. A document or standard that describes how to build such a connection or interface is called an ''API specification''. A computer system that meets this standard is said to ''implement'' or ''expose'' an API. The term API may refer either to the specification or to the implementation. In contrast to a user interface, which connects a computer to a person, an application programming interface connects computers or pieces of software to each other. It is not intended to be used directly by a person (the end user) other than a computer programmer who is incorporating it into software. An API is often made up of different parts which act as tools or services that are available to the programmer. A program or a programmer that uses one of these parts is said to ''call'' that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Refactoring
In computer programming and software design, code refactoring is the process of restructuring existing source code—changing the '' factoring''—without changing its external behavior. Refactoring is intended to improve the design, structure, and/or implementation of the software (its '' non-functional'' attributes), while preserving its functionality. Potential advantages of refactoring may include improved code readability and reduced complexity; these can improve the source code's maintainability and create a simpler, cleaner, or more expressive internal architecture or object model to improve extensibility. Another potential goal for refactoring is improved performance; software engineers face an ongoing challenge to write programs that perform faster or use less memory. Typically, refactoring applies a series of standardized basic ''micro-refactorings'', each of which is (usually) a tiny change in a computer program's source code that either preserves the behavior of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unit Testing
Unit testing, component or module testing, is a form of software testing by which isolated source code is tested to validate expected behavior. Unit testing describes tests that are run at the unit-level to contrast testing at the Integration testing, integration or System testing, system level. History Unit testing, as a principle for testing separately smaller parts of large software systems, dates back to the early days of software engineering. In June 1956 at US Navy's Symposium on Advanced Programming Methods for Digital Computers, H.D. Benington presented the Semi-Automatic Ground Environment, SAGE project. It featured a specification-based approach where the coding phase was followed by "parameter testing" to validate component subprograms against their specification, followed then by an "assembly testing" for parts put together. In 1964, a similar approach is described for the software of the Project Mercury, Mercury project, where individual units developed by dif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plug-in (computing)
In computing, a plug-in (also spelled plugin) or add-in (also addin, add-on, or addon) is a software component that extends the functionality of an existing software system without requiring the system to be software build, re-built. A plug-in software feature, feature is one way that a system can be customizable. Applications support plug-ins for a variety of reasons including: * Enable third-party developers to extend an application * Support easily adding new features * Reduce the size of an application by not loading unused features * Separate source code from an application because of incompatible software licenses Examples Examples of plug-in use for various categories of applications: * Digital audio workstations and audio editing software use audio plug-ins to generate, process or analyze sound. Ardour (software), Ardour, Audacity (audio editor), Audacity, Cubase, FL Studio, Logic Pro, Logic Pro X and Pro Tools are examples of such systems. * Email clients use plug-i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boilerplate Code
In computer programming, boilerplate code, or simply boilerplate, are sections of code that are repeated in multiple places with little to no variation. When using languages that are considered ''verbose'', the programmer must write a lot of boilerplate code to accomplish only minor functionality. The need for boilerplate can be reduced through high-level mechanisms such as metaprogramming (which has the computer automatically write the needed boilerplate code or insert it at compile time), convention over configuration (which provides good default values, reducing the need to specify program details in every project) and model-driven engineering (which uses models and model-to-code generators, eliminating the need for manual boilerplate code). It is also possible to move boilerplate code to an '' abstract class'' so that it can be inherited by any number of '' concrete classes''. Another option would be to move it into a subroutine so that it can be called instead of being du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Car
An electric car or electric vehicle (EV) is a passenger car, passenger automobile that is propelled by an electric motor, electric traction motor, using electrical energy as the primary source of propulsion. The term normally refers to a plug-in electric vehicle, typically a battery electric vehicle (BEV), which only uses energy stored in electric vehicle battery, on-board battery packs, but broadly may also include plug-in hybrid electric vehicle (PHEV), range extender, range-extended electric vehicle (REEV) and fuel cell electric vehicle (FCEV), which can convert electric power from other fuels via a electric generator, generator or a fuel cell. Compared to conventional internal combustion engine (ICE) vehicles, electric cars are quieter, more responsive, have superior energy conversion efficiency and no exhaust gas#Main motor vehicle emissions, exhaust emissions, as well as a typically lower overall carbon footprint from manufacturing to end of life (even when a power pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Fuel
Diesel fuel, also called diesel oil, heavy oil (historically) or simply diesel, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a result of compression of the inlet air and then injection of fuel. Therefore, diesel fuel needs good compression ignition characteristics. The most common type of diesel fuel is a specific fractional distillation, fractional distillate of petroleum fuel oil, but alternatives that are not derived from petroleum, such as biodiesel, biomass to liquid (BTL) or gas to liquid (GTL) diesel are increasingly being developed and adopted. To distinguish these types, petroleum-derived diesel is sometimes called petrodiesel in some academic circles. Diesel is a high-volume product of oil refineries. In many countries, diesel fuel is standardized. For example, in the European Union, the standard for diesel fuel is EN 590. Ultra-low-sulfur diesel (ULSD) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gasoline
Gasoline ( North American English) or petrol ( Commonwealth English) is a petrochemical product characterized as a transparent, yellowish, and flammable liquid normally used as a fuel for spark-ignited internal combustion engines. When formulated as a fuel for engines, gasoline is chemically composed of organic compounds derived from the fractional distillation of petroleum and later chemically enhanced with gasoline additives. It is a high-volume profitable product produced in crude oil refineries. The ability of a particular gasoline blend to resist premature ignition (which causes knocking and reduces efficiency in reciprocating engines) is measured by its octane rating. Tetraethyl lead was once widely used to increase the octane rating but is not used in modern automotive gasoline due to the health hazard. Aviation, off-road motor vehicles, and racing car engines still use leaded gasolines. Other substances are frequently added to gasoline to improve chemical st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Value Object
In computer science, a value object is a small object that represents a ''simple'' entity whose equality is not based on identity: i.e. two value objects are ''equal'' when they ''have'' the same ''value'', not necessarily being the ''same object''. Examples of value objects are objects representing an amount of money or a date range. Being small, one can have multiple copies of the same value object that represent the same ''entity'': it is often simpler to create a new object rather than rely on a single instance and use references to it. Value objects should be immutable: this is required for the implicit contract that two value objects created ''equal'', should remain equal. It is also useful for value objects to be immutable, as client code cannot put the value object in an invalid state or introduce buggy behaviour after instantiation. Value objects are among the building blocks of DDD. Implementation Due to the nuances of various object-oriented programming languages, ... [...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] |
Circular Dependency
In software engineering, a circular dependency is a relation between two or more modules which either directly or indirectly depend on each other to function properly. Such modules are also known as mutually recursive. Overview Circular dependencies are natural in many domain models where certain objects of the same domain depend on each other. However, in software design, circular dependencies between larger software modules are considered an anti-pattern because of their negative effects. Despite this, such circular (or cyclic) dependencies have been found to be widespread among the source files of real-world software. Mutually recursive modules are, however, somewhat common in functional programming, where inductive and recursive definitions are often encouraged. Problems Circular dependencies can cause many unwanted effects in software programs. Most problematic from a software design point of view is the ''tight coupling'' of the mutually dependent modules which reduces o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
