Portal:Computer programming

The Computer Programming Portal

Sample of computer program on a screen

---

Computer programming is the process of performing particular computations (or more generally, accomplishing specific computing results), usually by designing and building executable computer programs. Programming involves tasks such as analysis, generating algorithms, profiling algorithms' accuracy and resource consumption, and the implementation of algorithms (usually in a particular programming language, commonly referred to as coding). The source code of a program is written in one or more languages that are intelligible to programmers, rather than machine code, which is directly executed by the central processing unit. The purpose of programming is to find a sequence of instructions that will automate the performance of a task (which can be as complex as an operating system) on a computer, often for solving a given problem. Proficient programming thus usually requires expertise in several different subjects, including knowledge of the application domain, specialized algorithms, and formal logic.

Tasks accompanying and related to programming include testing, debugging, source code maintenance, implementation of build systems, and management of derived artifacts, such as the machine code of computer programs. However, while these might be considered part of the programming process, often the term software development is more likely used for this larger overall process – whereas the terms programming, implementation, and coding tend to be focused on the actual writing of code. Relatedly, software engineering combines engineering techniques and principles with software development. Also, those involved with software development may at times engage in reverse engineering, which is the practice of seeking to understand an existing program so as to re-implement its function in some way. (Full article...)

Selected articles -

• 

  Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers write once, run anywhere (WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but has fewer low-level facilities than either of them. The Java runtime provides dynamic capabilities (such as reflection and runtime code modification) that are typically not available in traditional compiled languages. , Java was one of the most popular programming languages in use according to GitHub, particularly for client–server web applications, with a reported 9 million developers.
  
  Java was originally developed by James Gosling at Sun Microsystems. It was released in May 1995 as a core component of Sun Microsystems' Java platform. The original and reference implementation Java compilers, virtual machines, and class libraries were originally released by Sun under proprietary licenses. As of May 2007, in compliance with the specifications of the Java Community Process, Sun had relicensed most of its Java technologies under the GPL-2.0-only license. Oracle offers its own HotSpot Java Virtual Machine, however the official reference implementation is the OpenJDK JVM which is free open-source software and used by most developers and is the default JVM for almost all Linux distributions.
  
  , Java 20 is the latest version, while Java 17, 11 and 8 are the current long-term support (LTS) versions. (Full article...)
• 

  

  A 12-row/80-column IBM punched card from the mid-twentieth century

  
  
  A punched card (also punch card or punched-card) is a piece of stiff paper that holds digital data represented by the presence or absence of holes in predefined positions. Punched cards were once common in data processing applications or to directly control automated machinery.
  
  Punched cards were widely used through much of the 20th century in the data processing industry, where specialized and increasingly complex unit record machines, organized into semiautomatic data processing systems, used punched cards for data input, output, and storage. The IBM 12-row/80-column punched card format came to dominate the industry. Many early digital computers used punched cards as the primary medium for input of both computer programs and data.
  
  While punched cards are now obsolete as a storage medium, as of 2012, some voting machines still used punched cards to record votes. Punched cards also had a significant cultural impact. (Full article...)
• 

  

  
  Kotlin (/ˈkɒtlɪn/) is a cross-platform, statically typed, general-purpose high-level programming language with type inference. Kotlin is designed to interoperate fully with Java, and the JVM version of Kotlin's standard library depends on the Java Class Library,
  
  but type inference allows its syntax to be more concise. Kotlin mainly targets the JVM, but also compiles to JavaScript (e.g., for frontend web applications using React) or native code via LLVM (e.g., for native iOS apps sharing business logic with Android apps). Language development costs are borne by JetBrains, while the Kotlin Foundation protects the Kotlin trademark.
  
  On 7 May 2019, Google announced that the Kotlin programming language was now its preferred language for Android app developers. Since the release of Android Studio 3.0 in October 2017, Kotlin has been included as an alternative to the standard Java compiler. The Android Kotlin compiler produces Java 8 bytecode by default (which runs in any later JVM), but lets the programmer choose to target Java 9 up to 19, for optimization, or allows for more features; has bidirectional record class interoperability support for JVM, introduced in Java 16, considered stable as of Kotlin 1.5. (Full article...)
• 

  

  A Blender 2.45 screenshot displaying the 3D test model Suzanne

  
  
  Computer graphics deals with generating images and art with the aid of computers. Today, computer graphics is a core technology in digital photography, film, video games, digital art, cell phone and computer displays, and many specialized applications. A great deal of specialized hardware and software has been developed, with the displays of most devices being driven by computer graphics hardware. It is a vast and recently developed area of computer science. The phrase was coined in 1960 by computer graphics researchers Verne Hudson and William Fetter of Boeing. It is often abbreviated as CG, or typically in the context of film as computer generated imagery (CGI). The non-artistic aspects of computer graphics are the subject of computer science research.
  
  Some topics in computer graphics include user interface design, sprite graphics, rendering, ray tracing, geometry processing, computer animation, vector graphics, 3D modeling, shaders, GPU design, implicit surfaces, visualization, scientific computing, image processing, computational photography, scientific visualization, computational geometry and computer vision, among others. The overall methodology depends heavily on the underlying sciences of geometry, optics, physics, and perception.
  Computer graphics is responsible for displaying art and image data effectively and meaningfully to the consumer. It is also used for processing image data received from the physical world, such as photo and video content. Computer graphics development has had a significant impact on many types of media and has revolutionized animation, movies, advertising, and video games, in general. (Full article...)
• 

  Laboratory Virtual Instrument Engineering Workbench (LabVIEW) is a system-design platform and development environment for a visual programming language from National Instruments.
  
  The graphical language is named "G"; not to be confused with G-code. The G dataflow language was originally developed by LabVIEW. LabVIEW is commonly used for data acquisition, instrument control, and industrial automation on a variety of operating systems (OSs), including macOS and other versions of Unix and Linux, as well as Microsoft Windows.
  
  The latest versions of LabVIEW are LabVIEW 2023 Q1 (released in April 2023) and LabVIEW NXG 5.1 (released in January 2021). NI released the free for non-commercial use LabVIEW and LabVIEW NXG Community editions on April 28, 2020. (Full article...)
• 

  
  

  

  Jobs introducing the iPhone 4 in 2010

  
  Steven Paul Jobs (February 24, 1955 – October 5, 2011) was an American business magnate, inventor, and investor. He was the co-founder, chairman, and CEO of Apple; the chairman and majority shareholder of Pixar; a member of The Walt Disney Company's board of directors following its acquisition of Pixar; and the founder, chairman, and CEO of NeXT. He was a pioneer of the personal computer revolution of the 1970s and 1980s, along with his early business partner and fellow Apple co-founder Steve Wozniak.
  
  Jobs was born in San Francisco to a Syrian father and German-American mother. He was adopted shortly after his birth. Jobs attended Reed College in 1972 before withdrawing that same year. In 1974, he traveled through India seeking enlightenment before later studying Zen Buddhism. He and Wozniak co-founded Apple in 1976 to sell Wozniak's Apple I personal computer. Together the duo gained fame and wealth a year later with production and sale of the Apple II, one of the first highly successful mass-produced microcomputers. Jobs saw the commercial potential of the Xerox Alto in 1979, which was mouse-driven and had a graphical user interface (GUI). This led to the development of the unsuccessful Apple Lisa in 1983, followed by the breakthrough Macintosh in 1984, the first mass-produced computer with a GUI. The Macintosh introduced the desktop publishing industry in 1985 with the addition of the Apple LaserWriter, the first laser printer to feature vector graphics.
  
  In 1985, Jobs was forced out of Apple after a long power struggle with the company's board and its then-CEO, John Sculley. That same year, Jobs took a few Apple employees with him to found NeXT, a computer platform development company that specialized in computers for higher-education and business markets. In addition, he helped to develop the visual effects industry when he funded the computer graphics division of George Lucas's Lucasfilm in 1986. The new company was Pixar, which produced the first 3D computer-animated feature film Toy Story (1995) and went on to become a major animation studio, producing over 25 films since. (Full article...)
• 

  

  
  Lisp (historically LISP, an acronym for list processing) is a family of programming languages with a long history and a distinctive, fully parenthesized prefix notation.
  Originally specified in 1960, Lisp is the second-oldest high-level programming language still in common use, after Fortran. Lisp has changed since its early days, and many dialects have existed over its history. Today, the best-known general-purpose Lisp dialects are Common Lisp, Scheme, Racket and Clojure.
  
  Lisp was originally created as a practical mathematical notation for computer programs, influenced by (though not originally derived from) the notation of Alonzo Church's lambda calculus. It quickly became a favored programming language for artificial intelligence (AI) research. As one of the earliest programming languages, Lisp pioneered many ideas in computer science, including tree data structures, automatic storage management, dynamic typing, conditionals, higher-order functions, recursion, the self-hosting compiler, and the read–eval–print loop.
  
  The name LISP derives from "LISt Processor". Linked lists are one of Lisp's major data structures, and Lisp source code is made of lists. Thus, Lisp programs can manipulate source code as a data structure, giving rise to the macro systems that allow programmers to create new syntax or new domain-specific languages embedded in Lisp. (Full article...)
• 

  

  
  Node.js is a cross-platform, open-source server environment that can run on Windows, Linux, Unix, macOS, and more. Node.js is a back-end JavaScript runtime environment, runs on the V8 JavaScript Engine, and executes JavaScript code outside a web browser.
  
  Node.js lets developers use JavaScript to write command line tools and for server-side scripting. The ability to run JavaScript code on the server is often used to generate dynamic web page content before the page is sent to the user's web browser. Consequently, Node.js represents a "JavaScript everywhere" paradigm, unifying web-application development around a single programming language, as opposed to using different languages for the server- versus client-side programming.
  
  Node.js has an event-driven architecture capable of asynchronous I/O. These design choices aim to optimize throughput and scalability in web applications with many input/output operations, as well as for real-time Web applications (e.g., real-time communication programs and browser games). (Full article...)
• 

  
  

  

  Babbage in 1860

  
  Charles Babbage KH FRS (/ˈbæbɪdʒ/; 26 December 1791 – 18 October 1871) was an English polymath. A mathematician, philosopher, inventor and mechanical engineer, Babbage originated the concept of a digital programmable computer.
  
  Babbage is considered by some to be "father of the computer". Babbage is credited with inventing the first mechanical computer, the Difference Engine, that eventually led to more complex electronic designs, though all the essential ideas of modern computers are to be found in Babbage's Analytical Engine, programmed using a principle openly borrowed from the Jacquard loom. Babbage had a broad range of interests in addition to his work on computers covered in his book Economy of Manufactures and Machinery. His varied work in other fields has led him to be described as "pre-eminent" among the many polymaths of his century.
  
  Babbage, who died before the complete successful engineering of many of his designs, including his Difference Engine and Analytical Engine, remained a prominent figure in the ideating of computing. Parts of Babbage's incomplete mechanisms are on display in the Science Museum in London. In 1991, a functioning difference engine was constructed from Babbage's original plans. Built to tolerances achievable in the 19th century, the success of the finished engine indicated that Babbage's machine would have worked. (Full article...)
• 

  

  The source code for a simple computer program written in the C programming language. The gray lines are comments that help explain the program to humans in a natural language. When compiled and run, it will give the output "Hello, world!".

  
  
  A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language.
  
  The description of a programming language is usually split into the two components of syntax (form) and semantics (meaning), which are usually defined by a formal language. Some languages are defined by a specification document (for example, the C programming language is specified by an ISO Standard) while other languages (such as Perl) have a dominant implementation that is treated as a reference. Some languages have both, with the basic language defined by a standard and extensions taken from the dominant implementation being common.
  
  Programming language theory is the subfield of computer science that studies the design, implementation, analysis, characterization, and classification of programming languages. (Full article...)
• 

  

  Logo since August 17, 2012

  
  Microsoft is a multinational computer technology corporation. Microsoft was founded on April 4, 1975, by Bill Gates and Paul Allen in Albuquerque, New Mexico. Its current best-selling products are the Microsoft Windows operating system; Microsoft Office, a suite of productivity software; Xbox, a line of entertainment of games, music, and video; Bing, a line of search engines; and Microsoft Azure, a cloud services platform.
  
  In 1980, Microsoft formed a partnership with IBM to bundle Microsoft's operating system with IBM computers; with that deal, IBM paid Microsoft a royalty for every sale. In 1985, IBM requested Microsoft to develop a new operating system for their computers called OS/2. Microsoft produced that operating system, but also continued to sell their own alternative, which proved to be in direct competition with OS/2. Microsoft Windows eventually overshadowed OS/2 in terms of sales. When Microsoft launched several versions of Microsoft Windows in the 1990s, they had captured over 90% market share of the world's personal computers.
  
  As of June 30, 2015, Microsoft has a global annual revenue of US$86.83 Billion and 128,076 employees worldwide. It develops, manufactures, licenses, and supports a wide range of software products for computing devices. (Full article...)
• 

  

  PDP-11 CPU board

  
  
  Computer hardware includes the physical parts of a computer, such as the case, central processing unit (CPU), random access memory (RAM), monitor, mouse, keyboard, computer data storage, graphics card, sound card, speakers and motherboard.
  
  By contrast, software is the set of instructions that can be stored and run by hardware. Hardware is so-termed because it is "hard" or rigid with respect to changes, whereas software is "soft" because it is easy to change.
  
  Hardware is typically directed by the software to execute any command or instruction. A combination of hardware and software forms a usable computing system, although other systems exist with only hardware. (Full article...)
• 

  
  

  

  Atari BASIC (1979) for the Atari 8-bit family

  
  BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College in 1963. They wanted to enable students in non-scientific fields to use computers. At the time, nearly all computers required writing custom software, which only scientists and mathematicians tended to learn.
  
  In addition to the program language, Kemeny and Kurtz developed the Dartmouth Time Sharing System (DTSS), which allowed multiple users to edit and run BASIC programs simultaneously on remote terminals. This general model became very popular on minicomputer systems like the PDP-11 and Data General Nova in the late 1960s and early 1970s. Hewlett-Packard produced an entire computer line for this method of operation, introducing the HP2000 series in the late 1960s and continuing sales into the 1980s. Many early video games trace their history to one of these versions of BASIC.
  
  The emergence of microcomputers in the mid-1970s led to the development of multiple BASIC dialects, including Microsoft BASIC in 1975. Due to the tiny main memory available on these machines, often 4 KB, a variety of Tiny BASIC dialects were also created. BASIC was available for almost any system of the era, and became the de facto programming language for home computer systems that emerged in the late 1970s. These PCs almost always had a BASIC interpreter installed by default, often in the machine's firmware or sometimes on a ROM cartridge. (Full article...)
• 

  

  
  Scala (/ˈskɑːlə/ SKAH-lah) is a strong statically typed high-level general-purpose programming language that supports both object-oriented programming and functional programming. Designed to be concise, many of Scala's design decisions are aimed to address criticisms of Java.
  
  Scala source code can be compiled to Java bytecode and run on a Java virtual machine (JVM). Scala can also be compiled to JavaScript to run in a browser, or directly to a native executable. On the JVM Scala provides language interoperability with Java so that libraries written in either language may be referenced directly in Scala or Java code. Like Java, Scala is object-oriented, and uses a syntax termed curly-brace which is similar to the language C. Since Scala 3, there is also an option to use the off-side rule (indenting) to structure blocks, and its use is advised. Martin Odersky has said that this turned out to be the most productive change introduced in Scala 3.
  
  Unlike Java, Scala has many features of functional programming languages (like Scheme, Standard ML, and Haskell), including currying, immutability, lazy evaluation, and pattern matching. It also has an advanced type system supporting algebraic data types, covariance and contravariance, higher-order types (but not higher-rank types), anonymous types, operator overloading, optional parameters, named parameters, raw strings, and an experimental exception-only version of algebraic effects that can be seen as a more powerful version of Java's checked exceptions. (Full article...)
• 

  

  IBM's Blue Gene/P massively parallel supercomputer

  
  Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism. Parallelism has long been employed in high-performance computing, but has gained broader interest due to the physical constraints preventing frequency scaling. As power consumption (and consequently heat generation) by computers has become a concern in recent years, parallel computing has become the dominant paradigm in computer architecture, mainly in the form of multi-core processors.
  
  Parallel computing is closely related to concurrent computing—they are frequently used together, and often conflated, though the two are distinct: it is possible to have parallelism without concurrency, and concurrency without parallelism (such as multitasking by time-sharing on a single-core CPU). In parallel computing, a computational task is typically broken down into several, often many, very similar sub-tasks that can be processed independently and whose results are combined afterwards, upon completion. In contrast, in concurrent computing, the various processes often do not address related tasks; when they do, as is typical in distributed computing, the separate tasks may have a varied nature and often require some inter-process communication during execution.
  
  Parallel computers can be roughly classified according to the level at which the hardware supports parallelism, with multi-core and multi-processor computers having multiple processing elements within a single machine, while clusters, MPPs, and grids use multiple computers to work on the same task. Specialized parallel computer architectures are sometimes used alongside traditional processors, for accelerating specific tasks. (Full article...)

Selected images

• 

  An animation of the quicksort algorithm sorting an array of randomized values

• 

  Partial view of the Mandelbrot set. Step 1 of a zoom sequence: Gap between the "head" and the "body" also called the "seahorse valley".

• 

  A screenshot of GNU Emacs 22.0.91.1, from Ubuntu’s emacs-snapshot-gtk package.

• 

  Animation of a Non-uniform rational B-spline surface. Modeled and rendered in Cobalt.

• 

  An IBM Port-A-Punch punched card

• 

  A head crash on a modern hard disk drive

• 

  A view of the GNU nano Text editor version 6.0

• 

  Margaret Hamilton standing next to the navigation software that she and her MIT team produced for the Apollo Project.

• 

  Grace Hopper at the UNIVAC keyboard, c. 1960. Grace Brewster Murray: American mathematician and rear admiral in the U.S. Navy who was a pioneer in developing computer technology, helping to devise UNIVAC I. the first commercial electronic computer, and naval applications for COBOL (common-business-oriented language).

• 

  Stephen Wolfram is a British-American computer scientist, physicist, and businessman. He is known for his work in computer science, mathematics, and in theoretical physics.

• 

  A lone house. An image made using Blender 3D.

• 

  Bill Gosper's Glider Gun in action

• 

  Deep Blue was a chess-playing expert system run on a unique purpose-built IBM supercomputer. It was the first computer to win a game, and the first to win a match, against a reigning world champion under regular time controls. Photo taken at the Computer History Museum.

• 

  This image (when viewed in full size, 1000 pixels wide) contains 1 million pixels, each of a different color.

• 

  Ada Lovelace was an English mathematician and writer, chiefly known for her work on Charles Babbage's proposed mechanical general-purpose computer, the Analytical Engine. She was the first to recognize that the machine had applications beyond pure calculation, and to have published the first algorithm intended to be carried out by such a machine. As a result, she is often regarded as the first computer programmer.

• 

  Output from a (linearised) shallow water equation model of water in a bathtub. The water experiences 5 splashes which generate surface gravity waves that propagate away from the splash locations and reflect off of the bathtub walls.

• 

  Partial map of the Internet based on the January 15, 2005 data found on opte.org. Each line is drawn between two nodes, representing two IP addresses. The length of the lines are indicative of the delay between those two nodes. This graph represents less than 30% of the Class C networks reachable by the data collection program in early 2005.

• 

  GNOME Shell, GNOME Clocks, Evince, gThumb and GNOME Files at version 3.30, in a dark theme

Did you know? -

• ... that the programming language Acorn System BASIC was so non-standard that one commenter suggested that using it on the BBC Micro would be a disaster?
• ... that although the suffix automaton, a data structure used in computer science, was introduced in 1983, it appeared in a 1973 scholarly article as an auxiliary structure?
• ... that according to the Open Syllabus Project, Diana Hacker is the second most-read female author on college campuses after Kate L. Turabian?
• ... that David Ahl purchased BASIC-8 to sell with the PDP-8 when DEC management proved more interested in their own FOCAL language?
• ... that the hazards of artificial intelligence include algorithmic bias, blaming humans for machine errors, and human–robot collisions?
• ... that a mathematical conjecture about tiling space by cubes was transformed into a problem in graph theory that became a benchmark for clique-finding algorithms?

Subcategories

Select [►] to view subcategories

Computer programming

Algorithms

Anti-patterns

Computer programming books

Code refactoring

Concurrent computing

Programming constructs

Data structures

Debugging

DLL injection

Computer programming folklore

Programming games

Indexes of computer topics

Computer libraries

Live coding

Method (computer programming)

Program derivation

Software optimization

Computer programmers

Programming contests

Programming idioms

Programming language syntax

Programming language topics

Programming languages

Programming paradigms

Programming principles

Quantum programming

Self-hosting software

Software design

Software design patterns

Source code

Source code generation

Streaming algorithms

Programming tools

Visual programming

Wikis about programming

Computer programming stubs

WikiProjects

There are many users interested in computer programming, join them.

• WikiProject Computing
• WikiProject Computer science
• WikiProject C/C++
• WikiProject Java
• WikiProject Cryptography
• WikiProject Software

Computer programming news

See also: Timeline of computing 2020–present § 2023

No recent news

Topics

Select [show] to view subtopics

Related portals

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject:

• 
  Commons
  Free media repository
• 
  Wikibooks
  Free textbooks and manuals
• 
  Wikidata
  Free knowledge base
• 
  Wikinews
  Free-content news
• 
  Wikiquote
  Collection of quotations
• 
  Wikisource
  Free-content library
• 
  Wikiversity
  Free learning tools
• 
  Wiktionary
  Dictionary and thesaurus

Discover Wikipedia using portals

• 
  List of all portals
• 
  The arts portal
• 
  Biography portal
• 
  Current events portal
• 
  Geography portal
• 
  History portal
• 
  Mathematics portal
• 
  Science portal
• 
  Society portal
• 
  Technology portal
• 
  Random portal
• 
  WikiProject Portals