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God Object
In object-oriented programming, a god object (sometimes also called an omniscient or all-knowing object) is an object that references a large number of distinct types, has too many unrelated or uncategorized methods, or some combination of both. The god object is an example of an anti-pattern and a code smell. A common programming technique is to separate a large problem into several smaller problems (a divide and conquer strategy) and create solutions for each of them. Once the smaller problems are solved, the big problem as a whole has been solved. Therefore a given object for a small problem only needs to know about itself. Likewise, there is only one set of problems an object needs to solve: its ''own'' problems. This also follows Single-responsibility principle. In contrast, a program that employs a god object does not follow this approach. Most of such a program's overall functionality is coded into a single "all-knowing" object, which maintains most of the information ... [...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] |
Object (computer Science)
In computer science, an object can be a variable, a data structure, a function, or a method. As regions of memory, they contain value and are referenced by identifiers. In the object-oriented programming paradigm, ''object'' can be a combination of variables, functions, and data structures; in particular in class-based variations of the paradigm it refers to a particular instance of a class. In the relational model of database management, an object can be a table or column, or an association between data and a database entity (such as relating a person's age to a specific person). Object-based languages An important distinction in programming languages is the difference between an object-oriented language and an object-based language. A language is usually considered object-based if it includes the basic capabilities for an object: identity, properties, and attributes. A language is considered object-oriented if it is object-based and also has the capability of polymorphism, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-pattern
An anti-pattern in software engineering, project management, and business processes is a common response to a recurring problem that is usually ineffective and risks being highly counterproductive. The term, coined in 1995 by computer programmer Andrew Koenig (programmer), Andrew Koenig, was inspired by the book ''Design Patterns (book), Design Patterns'' (which highlights a number of design patterns in software development that its authors considered to be highly reliable and effective) and first published in his article in the ''Journal of Object-Oriented Programming''. A further paper in 1996 presented by Michael Ackroyd at the Object World West Conference also documented anti-patterns. It was, however, the 1998 book ''AntiPatterns'' that both popularized the idea and extended its scope beyond the field of software design to include software architecture and project management. Other authors have extended it further since to encompass environmental/organizational/cultural anti-pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Smell
In computer programming, a code smell is any characteristic in the source code of a program that possibly indicates a deeper problem. Determining what is and is not a code smell is subjective, and varies by language, developer, and development methodology. The term was popularised by Kent Beck on WardsWiki in the late 1990s. Usage of the term increased after it was featured in the 1999 book ''Refactoring: Improving the Design of Existing Code'' by Martin Fowler. It is also a term used by agile programmers. Definition One way to look at smells is with respect to principles and quality: "Smells are certain structures in the code that indicate violation of fundamental design principles and negatively impact design quality". Code smells are usually not bugs; they are not technically incorrect and do not prevent the program from functioning. Instead, they indicate weaknesses in design that may slow down development or increase the risk of bugs or failures in the future. Bad code sme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Separation Of Concerns
In computer science, separation of concerns is a design principle for separating a computer program into distinct sections. Each section addresses a separate '' concern'', a set of information that affects the code of a computer program. A concern can be as general as "the details of the hardware for an application", or as specific as "the name of which class to instantiate". A program that embodies SoC well is called a modular program. Modularity, and hence separation of concerns, is achieved by encapsulating information inside a section of code that has a well-defined interface. Encapsulation is a means of information hiding. Layered designs in information systems are another embodiment of separation of concerns (e.g., presentation layer, business logic layer, data access layer, persistence layer). Separation of concerns results in more degrees of freedom for some aspect of the program's design, deployment, or usage. Common among these is increased freedom for simplification and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Divide And Conquer Algorithm
In computer science, divide and conquer is an algorithm design paradigm. A divide-and-conquer algorithm recursively breaks down a problem into two or more sub-problems of the same or related type, until these become simple enough to be solved directly. The solutions to the sub-problems are then combined to give a solution to the original problem. The divide-and-conquer technique is the basis of efficient algorithms for many problems, such as sorting (e.g., quicksort, merge sort), multiplying large numbers (e.g., the Karatsuba algorithm), finding the closest pair of points, syntactic analysis (e.g., top-down parsers), and computing the discrete Fourier transform (FFT). Designing efficient divide-and-conquer algorithms can be difficult. As in mathematical induction, it is often necessary to generalize the problem to make it amenable to a recursive solution. The correctness of a divide-and-conquer algorithm is usually proved by mathematical induction, and its computational cost is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-responsibility Principle
The single-responsibility principle (SRP) is a computer programming principle that states that "A module should be responsible to one, and only one, actor." The term actor refers to a group (consisting of one or more stakeholders or users) that requires a change in the module. Robert C. Martin, the originator of the term, expresses the principle as, "A class should have only one reason to change". Because of confusion around the word "reason" he has also clarified saying that the "principle is about people." In some of his talks, he also argues that the principle is, in particular, about roles or actors. For example, while they might be the same person, the role of an accountant is different from a database administrator. Hence, each module should be responsible for each role. History The term was introduced by Robert C. Martin in his article "The Principles of OOD" as part of his ''Principles of Object Oriented Design'', made popular by his 2003 book ''Agile Software Developmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subroutine
In computer programming, a function or subroutine is a sequence of program instructions that performs a specific task, packaged as a unit. This unit can then be used in programs wherever that particular task should be performed. Functions may be defined within programs, or separately in libraries that can be used by many programs. In different programming languages, a function may be called a routine, subprogram, subroutine, method, or procedure. Technically, these terms all have different definitions, and the nomenclature varies from language to language. The generic umbrella term ''callable unit'' is sometimes used. A function is often coded so that it can be started several times and from several places during one execution of the program, including from other functions, and then branch back (''return'') to the next instruction after the ''call'', once the function's task is done. The idea of a subroutine was initially conceived by John Mauchly during his work on ENIAC, ... [...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] |
Procedural Programming
Procedural programming is a programming paradigm, derived from imperative programming, based on the concept of the ''procedure call''. Procedures (a type of routine or subroutine) simply contain a series of computational steps to be carried out. Any given procedure might be called at any point during a program's execution, including by other procedures or itself. The first major procedural programming languages appeared circa 1957–1964, including Fortran, ALGOL, COBOL, PL/I and BASIC. Pascal and C were published circa 1970–1972. Computer processors provide hardware support for procedural programming through a stack register and instructions for calling procedures and returning from them. Hardware support for other types of programming is possible, but no attempt was commercially successful (for example Lisp machines or Java processors). Procedures and modularity Modularity is generally desirable, especially in large, complicated programs. Inputs are usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Variable
In computer programming, a global variable is a variable with global scope, meaning that it is visible (hence accessible) throughout the program, unless shadowed. The set of all global variables is known as the ''global environment'' or ''global state.'' In compiled languages, global variables are generally static variables, whose extent (lifetime) is the entire runtime of the program, though in interpreted languages (including command-line interpreters), global variables are generally dynamically allocated when declared, since they are not known ahead of time. In some languages, all variables are global, or global by default, while in most modern languages variables have limited scope, generally lexical scope, though global variables are often available by declaring a variable at the top level of the program. In other languages, however, global variables do not exist; these are generally modular programming languages that enforce a module structure, or class-based object-oriente ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcontroller
A microcontroller (MCU for ''microcontroller unit'', often also MC, UC, or μC) is a small computer on a single VLSI integrated circuit (IC) chip. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable input/output peripherals. Program memory in the form of ferroelectric RAM, NOR flash or OTP ROM is also often included on chip, as well as a small amount of RAM. Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications consisting of various discrete chips. In modern terminology, a microcontroller is similar to, but less sophisticated than, a system on a chip (SoC). An SoC may connect the external microcontroller chips as the motherboard components, but an SoC usually integrates the advanced peripherals like graphics processing unit (GPU) and Wi-Fi interface controller as its internal microcontroller unit circuits. Microcontrollers are use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
