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Software Package Metrics
Various software package metrics are used in modular programming. They have been mentioned by Robert Cecil Martin in his 2002 book ''Agile software development: principles, patterns, and practices''. The term software package here refers to a group of related classes in object-oriented programming. * Number of classes and interfaces: The number of concrete and abstract classes (and interfaces) in the package is an indicator of the extensibility of the package. * Afferent couplings (Ca): The number of classes in other packages that depend upon classes within the package is an indicator of the package's responsibility. Afferent couplings signal inward. * Efferent couplings (Ce): The number of classes in other packages that the classes in a package depend upon is an indicator of the package's dependence on externalities. Efferent couplings signal outward. * Abstractness (A): The ratio of the number of abstract classes (and interfaces) in the analyzed package to the total number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modular Programming
Modular programming is a software design technique that emphasizes separating the functionality of a program into independent, interchangeable modules, such that each contains everything necessary to execute only one aspect of the desired functionality. A module interface expresses the elements that are provided and required by the module. The elements defined in the interface are detectable by other modules. The implementation contains the working code that corresponds to the elements declared in the interface. Modular programming is closely related to structured programming and object-oriented programming, all having the same goal of facilitating construction of large software programs and systems by decomposition into smaller pieces, and all originating around the 1960s. While the historical usage of these terms has been inconsistent, "modular programming" now refers to the high-level decomposition of the code of an entire program into pieces: structured programming to the low-l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Cecil Martin
Robert Cecil Martin (born 5 December 1952), colloquially called "Uncle Bob", is an American software engineer, instructor, and best-selling author. He is most recognized for developing many software design principles and for being a founder of the influential Agile Manifesto. Martin has authored many books and magazine articles. He was the editor-in-chief of ''C++ Report'' magazine and served as the first chairman of the Agile Alliance. Companies In 1991, Martin founded Object Mentor, now defunct, which provided instructor-led training on the extreme programming methodology. , he operated two companies: *Uncle Bob Consulting – provides consulting and training services *Clean Coders – which provides training videos Software principles and advocacy Five of Martin's principles have become known collectively as the ''SOLID principles''. Though he invented most of the principles he promotes, the Liskov substitution principle was invented by Barbara Liskov, while the open–c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Package Manager
A package manager or package-management system is a collection of software tools that automates the process of installing, upgrading, configuring, and removing computer programs for a computer in a consistent manner. A package manager deals with ''packages'', distributions of software and data in archive files. Packages contain metadata, such as the software's name, description of its purpose, version number, vendor, checksum (preferably a cryptographic hash function), and a list of dependencies necessary for the software to run properly. Upon installation, metadata is stored in a local package database. Package managers typically maintain a database of software dependencies and version information to prevent software mismatches and missing prerequisites. They work closely with software repositories, binary repository managers, and app stores. Package managers are designed to eliminate the need for manual installs and updates. This can be particularly useful for large enterp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class (computer Science)
In object-oriented programming, a class is an extensible program-code-template for creating objects, providing initial values for state (member variables) and implementations of behavior (member functions or methods). In many languages, the class name is used as the name for the class (the template itself), the name for the default constructor of the class (a subroutine that creates objects), and as the type of objects generated by instantiating the class; these distinct concepts are easily conflated. Although, to the point of conflation, one could argue that is a feature inherent in a language because of its polymorphic nature and why these languages are so powerful, dynamic and adaptable for use compared to languages without polymorphism present. Thus they can model dynamic systems (i.e. the real world, machine learning, AI) more easily. When an object is created by a constructor of the class, the resulting object is called an instance of the class, and the member variabl ... [...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 imper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coupling (computer Programming)
In software engineering, coupling is the degree of interdependence between software modules; a measure of how closely connected two routines or modules are; the strength of the relationships between modules. Coupling is usually contrasted with cohesion. Low coupling often correlates with high cohesion, and vice versa. Low coupling is often thought to be a sign of a well-structured computer system and a good design, and when combined with high cohesion, supports the general goals of high readability and maintainability. History The software quality metrics of coupling and cohesion were invented by Larry Constantine in the late 1960s as part of a structured design, based on characteristics of “good” programming practices that reduced maintenance and modification costs. Structured design, including cohesion and coupling, were published in the article ''Stevens, Myers & Constantine'' (1974) and the book ''Yourdon & Constantine'' (1979), and the latter subsequently became stan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afferent Couplings
Various software package metrics are used in modular programming. They have been mentioned by Robert Cecil Martin in his 2002 book ''Agile software development: principles, patterns, and practices''. The term software package here refers to a group of related classes in object-oriented programming. * Number of classes and interfaces: The number of concrete and abstract classes (and interfaces) in the package is an indicator of the extensibility of the package. * Afferent couplings (Ca): The number of classes in other packages that depend upon classes within the package is an indicator of the package's responsibility. Afferent couplings signal inward. * Efferent couplings (Ce): The number of classes in other packages that the classes in a package depend upon is an indicator of the package's dependence on externalities. Efferent couplings signal outward. * Abstractness (A): The ratio of the number of abstract classes (and interfaces) in the analyzed package to the total number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Efferent Coupling
Efferent coupling is a coupling metric in software development. It measures the number of data types a class knows about. This includes inheritance, interface implementation, parameter types, variable types, and exceptions. This has also been referred to by Robert C. Martin as the Fan-out stability metric which in his book Clean Architecture he describes as Outgoing dependencies. This metric identifies the number of classes inside this component that depend on classes outside the component. This metric is often used to calculate instability of a component in software architecture Software architecture is the fundamental structure of a software system and the discipline of creating such structures and systems. Each structure comprises software elements, relations among them, and properties of both elements and relations. ... as ''I'' = Fan-out / (Fan-in + Fan-out). This metric has a range ,1 ''I'' = 0 is maximally stable while ''I'' = 1 is maximally unstable. References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Efferent
Efferent may refer to: Anatomical structures Meaning 'conveying away from a center': *Efferent arterioles, conveying blood away from the Bowman's capsule in the kidney *Efferent nerve fiber, carries nerve impulses away from the central nervous system toward the peripheral effector organs *Efferent lymph vessel, lymph vessels that carry lymph from a lymph node *Efferent ducts, connect the rete testis with the initial section of the epididymis Other uses *Efferent coupling Efferent coupling is a coupling metric in software development. It measures the number of data types a class knows about. This includes inheritance, interface implementation, parameter types, variable types, and exceptions. This has also been ..., a metric in software development See also * Afferent (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dependency Inversion Principle
In object-oriented design, the dependency inversion principle is a specific methodology for loosely coupling software modules. When following this principle, the conventional dependency relationships established from high-level, policy-setting modules to low-level, dependency modules are reversed, thus rendering high-level modules independent of the low-level module implementation details. The principle states: By dictating that high-level and low-level objects must depend on the same abstraction, this design principle the way some people may think about object-oriented programming. The idea behind points A and B of this principle is that when designing the interaction between a high-level module and a low-level one, the interaction should be thought of as an abstract interaction between them. This not only has implications on the design of the high-level module, but also on the low-level one: the low-level one should be designed with the interaction in mind and it may be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Metrics
In software engineering and development, a software metric is a standard of measure of a degree to which a software system or process possesses some property. Even if a metric is not a measurement (metrics are functions, while measurements are the numbers obtained by the application of metrics), often the two terms are used as synonyms. Since quantitative measurements are essential in all sciences, there is a continuous effort by computer science practitioners and theoreticians to bring similar approaches to software development. The goal is obtaining objective, reproducible and quantifiable measurements, which may have numerous valuable applications in schedule and budget planning, cost estimation, quality assurance, testing, software debugging, software performance optimization, and optimal personnel task assignments. Common software measurements Common software measurements include: * ABC Software Metric * Balanced scorecard * Bugs per line of code * Code coverage * Cohe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
