Portal:Computer programming

COBOL (/ˈkoʊbɒl, -bɔːl/; an acronym for "common business-oriented language") is a compiled English-like computer programming language designed for business use. It is an imperative, procedural and, since 2002, object-oriented language. COBOL is primarily used in business, finance, and administrative systems for companies and governments. COBOL is still widely used in applications deployed on mainframe computers, such as large-scale batch and transaction processing jobs. However, due to its declining popularity and the retirement of experienced COBOL programmers, programs are being migrated to new platforms, rewritten in modern languages or replaced with software packages. Most programming in COBOL is now purely to maintain existing applications; however, many large financial institutions were still developing new systems in COBOL as late as 2006.

COBOL was designed in 1959 by CODASYL and was partly based on the programming language FLOW-MATIC designed by Grace Hopper. It was created as part of a US Department of Defense effort to create a portable programming language for data processing. It was originally seen as a stopgap, but the Department of Defense promptly forced computer manufacturers to provide it, resulting in its widespread adoption. It was standardized in 1968 and has since been revised five times. Expansions include support for structured and object-oriented programming. The current standard is ISO/IEC 1989:2023.

COBOL statements feature prose syntax such as MOVE x TO y, which was designed to be self-documenting and highly readable. However, it is verbose and uses over 300 reserved words. This contrasts with the succinct and mathematically-inspired syntax of other languages (in this case, y = x;). (Full article...)

The Antikythera mechanism (/ˌæntɪˈkɪθɪərə/ AN-tih-KIH-ther-ə) is an Ancient Greek hand-powered orrery (model of the Solar System), described as the oldest known example of an analogue computer used to predict astronomical positions and eclipses decades in advance. It could also be used to track the four-year cycle of athletic games which was similar to an Olympiad, the cycle of the ancient Olympic Games.

This artefact was among wreckage retrieved from a shipwreck off the coast of the Greek island Antikythera in 1901. In 1902, it was identified by archaeologist Valerios Stais as containing a gear. The device, housed in the remains of a wooden-framed case of (uncertain) overall size 34 cm × 18 cm × 9 cm (13.4 in × 7.1 in × 3.5 in), was found as one lump, later separated into three main fragments which are now divided into 82 separate fragments after conservation efforts. Four of these fragments contain gears, while inscriptions are found on many others. The largest gear is about 13 cm (5 in) in diameter and originally had 223 teeth.

In 2008, a team from Cardiff University used computer x-ray tomography and high resolution scanning to image inside fragments of the crust-encased mechanism and read the faintest inscriptions that once covered the outer casing. This suggests it had 37 meshing bronze gears enabling it to follow the movements of the Moon and the Sun through the zodiac, to predict eclipses and to model the irregular orbit of the Moon, where the Moon's velocity is higher in its perigee than in its apogee. This motion was studied in the 2nd century BC by astronomer Hipparchus of Rhodes, and he may have been consulted in the machine's construction. There is speculation that a portion of the mechanism is missing and it calculated the positions of the five classical planets. The inscriptions were further deciphered in 2016, revealing numbers connected with the synodic cycles of Venus and Saturn. (Full article...)

F# (pronounced F sharp) is a functional-first, general-purpose, strongly typed, multi-paradigm programming language that encompasses functional, imperative, and object-oriented programming methods. It is most often used as a cross-platform Common Language Infrastructure (CLI) language on .NET, but can also generate JavaScript and graphics processing unit (GPU) code.

F# is developed by the F# Software Foundation, Microsoft and open contributors. An open source, cross-platform compiler for F# is available from the F# Software Foundation. F# is a fully supported language in Visual Studio and JetBrains Rider. Plug-ins supporting F# exist for many widely used editors including Visual Studio Code, Vim, and Emacs.

F# is a member of the ML language family and originated as a .NET Framework implementation of a core of the programming language OCaml. It has also been influenced by C#,
Python, Haskell, Scala and Erlang. (Full article...)

Margaret Elaine Hamilton (née Heafield; born August 17, 1936) is an American computer scientist, systems engineer, and business owner. She was director of the Software Engineering Division of the MIT Instrumentation Laboratory, which developed on-board flight software for NASA's Apollo program. She later founded two software companies—Higher Order Software in 1976 and Hamilton Technologies in 1986, both in Cambridge, Massachusetts.

Hamilton has published more than 130 papers, proceedings, and reports, about sixty projects, and six major programs. She invented the term "software engineering", stating "I began to use the term ‘software engineering’ to distinguish it from hardware and other kinds of engineering, yet treat each type of engineering as part of the overall systems engineering process."

On November 22, 2016, Hamilton received the Presidential Medal of Freedom from president Barack Obama for her work leading to the development of on-board flight software for NASA's Apollo Moon missions. (Full article...)

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 1832 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 Appy Awards, presented on 11 April 2011, marked successful and popular applications (generally known as "apps") for mobile devices. Sponsored by The Carphone Warehouse, Europe's largest independent mobile phone retailer, awards were presented in ten categories in a ceremony hosted by television presenters Richard Hammond and Amanda Byram. According to the sponsors, it was "the UK's first major app awards ceremony designed to recognise innovation and development in app technology." The company hoped to make it an annual event.

Carphone Warehouse staff nominated around 1,000 apps from which a panel of judges produced a shortlist of 50, announced by Hammond in February 2011. In an online process, about 30,000 votes were cast by the public to choose the winners. Most of the shortlisted apps are free to download but others require a one-off or an ongoing payment. Finland-based Rovio Mobile's 2009 game Angry Birds, which recently passed the 100-million download mark, won the award for Best App of the Year along with a win in the Best Game App category and a nomination in the Best Time Waster App category. Lima Sky's Doodle Jump, which topped 10 million downloads in March 2011, was nominated in both the Best Game App and Best Time Waster App categories but failed to win either. Similarly ShopSavvy Barcode Scanner and Football Manager Handheld 2011 were nominated in two categories, both failing to win an award. As of 2016, no further Appy Awards have been made other than those in the inaugural ceremony. (Full article...)

Haskell (/ˈhæskəl/) is a general-purpose, statically-typed, purely functional programming language with type inference and lazy evaluation. Designed for teaching, research, and industrial applications, Haskell has pioneered a number of programming language features such as type classes, which enable type-safe operator overloading, and monadic input/output (IO). It is named after logician Haskell Curry. Haskell's main implementation is the Glasgow Haskell Compiler (GHC).

Haskell's semantics are historically based on those of the Miranda programming language, which served to focus the efforts of the initial Haskell working group. The last formal specification of the language was made in July 2010, while the development of GHC continues to expand Haskell via language extensions.

Haskell is used in academia and industry. , Haskell was the 28th most popular programming language by Google searches for tutorials, and made up less than 1% of active users on the GitHub source code repository. (Full article...)

William Henry Gates III (born October 28, 1955) is an American business magnate, investor, philanthropist, and writer best known for co-founding the software giant Microsoft, along with his childhood friend Paul Allen. During his career at Microsoft, Gates held the positions of chairman, chief executive officer (CEO), president, and chief software architect, while also being its largest individual shareholder until May 2014. He was a major entrepreneur of the microcomputer revolution of the 1970s and 1980s.

Gates was born and raised in Seattle, Washington. In 1975, he and Allen founded Microsoft in Albuquerque, New Mexico. It later became the world's largest personal computer software company. Gates led the company as its chairman and chief executive officer until stepping down as CEO in January 2000, succeeded by Steve Ballmer, but he remained chairman of the board of directors and became chief software architect. During the late 1990s, he was criticized for his business tactics, which were considered anti-competitive. This opinion has been upheld by numerous court rulings. In June 2008, Gates transitioned into a part-time role at Microsoft and full-time work at the Bill & Melinda Gates Foundation, the private charitable foundation he and his then-wife Melinda had established in 2000. He stepped down as chairman of the Microsoft board in February 2014 and assumed the role of technology adviser to support newly appointed CEO Satya Nadella. In March 2020, Gates left his board positions at Microsoft and Berkshire Hathaway to focus on his philanthropic efforts on climate change, global health and development, and education.

Since 1987, Gates has been included in the Forbes list of the world's billionaires. From 1995 to 2017, he held the Forbes title of the richest person in the world every year except in 2008 and from 2010 to 2013. In October 2017, he was surpassed by Amazon founder and CEO Jeff Bezos, who had an estimated net worth of US$90.6 billion compared to Gates's net worth of US$89.9 billion at the time. In the Forbes 400 list of wealthiest Americans in 2023, he was ranked 6th with a wealth of $111.0 billion. As of October 2023, Gates has an estimated net worth of US$123 billion, making him the fourth-richest person in the world according to Bloomberg Billionaires Index. (Full article...)

Mya was an intelligent personal assistant under development by Motorola. Proposed features for the program included the ability to read emails and answer questions 24 hours a day. Mya was intended to work with an internet service Motorola was developing called Myosphere, and was planned to be a paid service that would eventually be used by other mobile carriers. A female computer-generated character was created to represent Mya in advertising. While the quality of the character's animation was praised, it received criticism for being over sexualised.

Both the character and the program were announced to the public via an advertisement in March 2000, though the program was not ready for use at that time. Despite the announcement generating a considerable amount of attention, little was heard regarding the project in subsequent months. The program was never officially released nor cancelled, though the trademarks for both Myosphere and Mya were abandoned by Motorola in 2002. The name Mya was believed to be a play on the words 'My assistant'. (Full article...)

JavaScript (/ˈdʒɑːvəskrɪpt/), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. , 98.7% of websites use JavaScript on the client side for webpage behavior, often incorporating third-party libraries. All major web browsers have a dedicated JavaScript engine to execute the code on users' devices.

JavaScript is a high-level, often just-in-time compiled language that conforms to the ECMAScript standard. It has dynamic typing, prototype-based object-orientation, and first-class functions. It is multi-paradigm, supporting event-driven, functional, and imperative programming styles. It has application programming interfaces (APIs) for working with text, dates, regular expressions, standard data structures, and the Document Object Model (DOM).

The ECMAScript standard does not include any input/output (I/O), such as networking, storage, or graphics facilities. In practice, the web browser or other runtime system provides JavaScript APIs for I/O. (Full article...)

Computer programming or coding is the composition of sequences of instructions, called programs, that computers can follow to perform tasks. It involves designing and implementing algorithms, step-by-step specifications of procedures, by writing code in one or more programming languages. Programmers typically use high-level programming languages that are more easily intelligible to humans than machine code, which is directly executed by the central processing unit. Proficient programming usually requires expertise in several different subjects, including knowledge of the application domain, details of programming languages and generic code libraries, specialized algorithms, and formal logic.

Auxiliary tasks accompanying and related to programming include analyzing requirements, testing, debugging (investigating and fixing problems), implementation of build systems, and management of derived artifacts, such as programs' machine code. While these are sometimes considered programming, often the term software development is used for this larger overall process – with the terms programming, implementation, and coding reserved for the writing and editing of code per se. Sometimes software development is known as software engineering, especially when it employs formal methods or follows an engineering design process. (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...)

In SQL, null or NULL is a special marker used to indicate that a data value does not exist in the database. Introduced by the creator of the relational database model, E. F. Codd, SQL null serves to fulfil the requirement that all true relational database management systems (RDBMS) support a representation of "missing information and inapplicable information". Codd also introduced the use of the lowercase Greek omega (ω) symbol to represent null in database theory. In SQL, NULL is a reserved word used to identify this marker.

A null should not be confused with a value of 0. A null value indicates a lack of a value, which is not the same thing as a value of zero. For example, consider the question "How many books does Adam own?" The answer may be "zero" (we know that he owns none) or "null" (we do not know how many he owns). In a database table, the column reporting this answer would start out with no value (marked by Null), and it would not be updated with the value "zero" until we have ascertained that Adam owns no books.

SQL null is a marker, not a value. This usage is quite different from most programming languages, where null value of a reference means it is not pointing to any object. (Full article...)

Scala (/ˈskɑːlə/ SKAH-lah) is a strong statically typed high-level general-purpose programming language that is supporting 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...)

Tcl (pronounced "tickle" or as an initialism) is a high-level, general-purpose, interpreted, dynamic programming language. It was designed with the goal of being very simple but powerful. Tcl casts everything into the mold of a command, even programming constructs like variable assignment and procedure definition. Tcl supports multiple programming paradigms, including object-oriented, imperative, functional, and procedural styles.

It is commonly used embedded into C applications, for rapid prototyping, scripted applications, GUIs, and testing. Tcl interpreters are available for many operating systems, allowing Tcl code to run on a wide variety of systems. Because Tcl is a very compact language, it is used on embedded systems platforms, both in its full form and in several other small-footprint versions.

The popular combination of Tcl with the Tk extension is referred to as Tcl/Tk (pronounced "tickle teak" or as an initialism) and enables building a graphical user interface (GUI) natively in Tcl. Tcl/Tk is included in the standard Python installation in the form of Tkinter. (Full article...)