Computer Programming

Computer programming (often shortened to programming) is a process that leads from an original formulation of a computing problem to executable programs. It involves activities such as analysis, understanding, thinking, and generically solving such problems resulting in an algorithm, verification of requirements of the algorithm including its correctness and its resource consumption, implementation (commonly referred to as coding[1][2]) of the algorithm in a target programming language. Source code is written in one or more programming languages (such as C, C++, C#,Java, Python, Smalltalk, JavaScript, etc.). The purpose of programming is to find a sequence of instructions that will automate performing a specific task or solve a given problem.[citation needed] The process of programming thus often requires expertise in many different subjects, including knowledge of the application domain, specialized algorithmsand formal logic.
Related tasks include testing, debugging, and maintaining the source code, implementation of the build system, and management of derived artifacts such as machine code of computer programs. These might be considered part of the programming process, but often the term "software development" is used for this larger process with the term "programming", "implementation", or "coding" reserved for the actual writing of source code. Software engineeringcombines engineering techniques with software development practices
Computer programming (often shortened to programming) is a process that leads from an original formulation of a computing problem to executable programs. It involves activities such as analysis, understanding, thinking, and generically solving such problems resulting in an algorithm, verification of requirements of the algorithm including its correctness and its resource consumption, implementation (commonly referred to as coding[1][2]) of the algorithm in a target programming language. Source code is written in one or more programming languages (such as C, C++, C#,Java, Python, Smalltalk, JavaScript, etc.). The purpose of programming is to find a sequence of instructions that will automate performing a specific task or solve a given problem.[citation needed] The process of programming thus often requires expertise in many different subjects, including knowledge of the application domain, specialized algorithmsand formal logic.
Related tasks include testing, debugging, and maintaining the source code, implementation of the build system, and management of derived artifacts such as machine code of computer programs. These might be considered part of the programming process, but often the term "software development" is used for this larger process with the term "programming", "implementation", or "coding" reserved for the actual writing of source code. Software engineeringcombines engineering techniques with software development practices
A programmer, computer programmer, developer, coder, or software engineer is a person who writes computer software. The term computer programmer can refer to a specialist in one area of computer programming or to a generalist who writes code for many kinds of software. One who practices or professes a formal approach to programming may also be known as a programmer analyst. A programmer's primary computer language (C, C++, C#, Java, Lisp, Python, etc.) is often prefixed to the above titles, and those who work in a web environment often prefix their titles with Web. The termprogrammer can be used to refer to a software developer, Web developer, mobile applications developer, embeddedfirmware developer, software engineer, computer scientist, or software analyst. However, members of these professionspossess other software engineering skills, beyond programming; for this reason, the term programmer, or code monkey, is sometimes considered an insulting or derogatory oversimplification of these other professions.[1] This has sparked much debate amongst developers, analysts, computer scientists, programmers, and outsiders who continue to be puzzled at the subtle differences in the definitions of these occupations.[2][3][4][5][6]

Ada Lovelace, the first computer programmer.[7]
British countess and mathematician Ada Lovelace is considered the first computer programmer, as she was the first to write and publish an algorithm intended for implementation on Charles Babbage's analytical engine, in October 1842, intended for the calculation of Bernoulli numbers.[8] Lovelace was also the first person to comment on the potential for computers to be used for purposes other than computing calculations. Because Babbage's machine was never completed to a functioning standard in her time, she never saw her algorithm run.
The first person to run a program on a functioning modern electronically based computer was computer scientist Konrad Zuse, in 1941.
The ENIAC programming team, consisting of Kay McNulty, Betty Jennings, Betty Snyder, Marlyn Wescoff, Fran Bilas and Ruth Lichterman were the first regularly working programmers.[9][10]
International Programmers' Day is celebrated annually on 7 January.[11] In 2009, the government of Russia decreed a professional annual holiday known as Programmers' Day to be celebrated on 13 September (12 September in leap years). It had also been an unofficial international holiday before that.
Computer programmers write, test, debug, and maintain the detailed instructions, called computer programs, that computers must follow to perform their functions. Programmers also conceive, design, and test logical structures for solving problems by computer. Many technical innovations in programming — advanced computing technologies and sophisticated new languages and programming tools — have redefined the role of a programmer and elevated much of the programming work done today. Job titles and descriptions may vary, depending on the organization.
Programmers work in many settings, including corporate information technology ("IT") departments, big software companies, and small service firms. Many professional programmers also work for consulting companies at client sites as contractors. Licensing is not typically required to work as a programmer, although professional certificationsare commonly held by programmers. Programming is widely considered a profession (although some[who?]authorities disagree on the grounds that only careers with legal licensing requirements count as a profession).
Programmers' work varies widely depending on the type of business for which they are writing programs. For example, the instructions involved in updating financial records are very different from those required to duplicate conditions on an aircraft for pilots training in a flight simulator. Simple programs can be written in a few hours, more complex ones may require more than a year of work, while others are never considered 'complete' but rather are continuously improved as long as they stay in use. In most cases, several programmers work together as a team under a senior programmer’s supervision.
Programmers write programs according to the specifications determined primarily by more senior programmers and by systems analysts. After the design process is complete, it is the job of the programmer to convert that design into a logical series of instructions that the computer can follow. The programmer codes these instructions in one of many programming languages. Different programming languages are used depending on the purpose of the program. COBOL, for example, is commonly used for business applications that typically run on mainframe and midrange computers, whereas Fortran is used in science and engineering. C++ is widely used for both scientific and business applications. Java, C#, VB and PHP are popular programming languages for Web and business applications. Programmers generally know more than one programming language and, because many languages are similar, they often can learn new languages relatively easily. In practice, programmers often are referred to by the language they know, e.g. as Java programmers, or by the type of function they perform or environment in which they work: for example, database programmers, mainframe programmers, or Web developers.
When making changes to the source code that programs are made up of, programmers need to make other programmers aware of the task that the routine is to perform. They do this by inserting comments in the source code so that others can understand the program more easily and by documenting their code. To save work, programmers often use libraries of basic code that can be modified or customized for a specific application. This approach yields more reliable and consistent programs and increases programmers' productivity by eliminating some routine steps.
Testing and debugging[edit]
Programmers test a program by running it and looking for bugs (errors). As they are identified, the programmer usually makes the appropriate corrections, then rechecks the program until an acceptably low level and severity of bugs remain. This process is called testing and debugging. These are important parts of every programmer's job. Programmers may continue to fix these problems throughout the life of a program. Updating, repairing, modifying, and expanding existing programs is sometimes called maintenance programming. Programmers may contribute to user guides and online help, or they may work with technical writers to do such work.
Computer programmers are those who write computer software. Their jobs usually involve:
Coding
Debugging
Documentation
Integration
Maintenance
Requirements analysis
Software architecture
Software testing
Specification
A computer program, or just a program, is a sequence of instructions, written to perform a specified task with acomputer.[1] A computer requires programs to function, typically executing the program's instructions in a central processor.[2] The program has an executable form that the computer can use directly to execute the instructions. The same program in its human-readable source code form, from which executable programs are derived (e.g., compiled), enables aprogrammer to study and develop its algorithms. A collection of computer programs and related data is referred to as thesoftware.
Computer source code is typically written by computer programmers.[3] Source code is written in a programming languagethat usually follows one of two main paradigms: imperative or declarative programming. Source code may be converted into an executable file (sometimes called an executable program or a binary) by a compiler and later executed by a central processing unit. Alternatively, computer programs may be executed with the aid of an interpreter, or may be embeddeddirectly into hardware.
Computer programs may be ranked along functional lines: system software and application software. Two or more computer programs may run simultaneously on one computer from the perspective of the user, this process being known asmultitasking.
Embedded programs[edit]

The microcontroller on the right of thisUSB flash drive is controlled with embedded firmware.
Some computer programs are embedded into hardware. A stored-program computer requires an initial computer program stored in its read-only memory to boot. The boot process is to identify and initialize all aspects of the system, fromprocessor registers to device controllers to memory contents.[9] Following the initialization process, this initial computer program loads the operating system and sets the program counter to begin normal operations. Independent of the host computer, a hardware device might have embedded firmware to control its operation. Firmware is used when the computer program is rarely or never expected to change, or when the program must not be lost when the power is off.[10]
Manual programming[edit]

Switches for manual input on a Data General Nova 3
Computer programs historically were manually input to the central processor via switches. An instruction was represented by a configuration of on/off settings. After setting the configuration, an execute button was pressed. This process was then repeated. Computer programs also historically were manually input via paper tape or punched cards. After the medium was loaded, the starting address was set via switches and the execute button pressed.[11]
Automatic program generation[edit]
Generative programming is a style of computer programming that creates source code through generic classes,prototypes, templates, aspects, and code generators to improve programmer productivity. Source code is generated withprogramming tools such as a template processor or an integrated development environment. The simplest form of source code generator is a macro processor, such as the C preprocessor, which replaces patterns in source code according to relatively simple rules.
Software engines output source code or markup code that simultaneously become the input to another computer process.Application servers are software engines that deliver applications to client computers. For example, a Wiki is an application server that lets users build dynamic content assembled from articles. Wikis generate HTML, CSS, Java, and JavaScriptwhich are then interpreted by a web browser.
An organized list of instructions that, when executed, causes thecomputerto behave in a predetermined manner. Without programs, computers are useless.
A program is like a recipe. It contains a list of ingredients (calledvariables) and a list of directions (called statements) that tell the computer what to do with the variables. The variables can represent numeric data, text, or graphical images.
There are many programming languages -- C, C++, Pascal, BASIC,FORTRAN, COBOL, and LISP are just a few. These are all high-level languages. One can also write programs in low-level languages called assembly languages, although this is more difficult. Low-level languages are closer to thelanguageused by a computer, while high-level languages are closer to human languages.

(1) Data is distinct pieces of information, usually formatted in a special way. All software is divided into two general categories:data and programs. Programs are collections of instructions for manipulating data.
Data can exist in a variety of forms -- as numbers or text on pieces of paper, as bits and bytes stored in electronic memory, or as facts stored in a person's mind.
Strictly speaking, data is the plural of datum, a single piece of information. In practice, however, people use data as both the singular and plural form of the word.