Parameter (computer programming)

In computer programming, a parameter is a special kind of variable, used in a subroutine to refer to one of the pieces of data provided as input to the subroutine. These pieces of data are called arguments. An ordered list of parameters is usually included in the definition of a subroutine, so that, each time the subroutine is called, its arguments for that call can be assigned to the corresponding parameters.

Just as in standard mathematical usage, the argument is thus the actual input passed to a function, procedure, or routine, whereas the parameter is the variable inside the implementation of the subroutine. For example, if one defines the add subroutine as def add(x, y): return x + y, then x, y are parameters, while if this is called as add(2, 3), then 2, 3 are the arguments. Note that variables from the calling context can be arguments: if the subroutine is called as a = 2; b = 3; add(a, b) then the variables a, b are the arguments, not only the values 2, 3. See the Parameters and arguments section for more information.

Computer programming

Computer programming (often shortened to programming) is a process that leads from an original formulation of a computing problem to executable computer programs. Programming involves activities such as analysis, developing understanding, generating algorithms, verification of requirements of algorithms including their correctness and resources consumption, and implementation (commonly referred to as coding) of algorithms in a target programming language. Source code is written in one or more programming languages. The purpose of programming is to find a sequence of instructions that will automate performing a specific task or solving a given problem. The process of programming thus often requires expertise in many different subjects, including knowledge of the application domain, specialized algorithms and 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 engineering combines engineering techniques with software development practices.

Programming

Programming may refer to:

See also

Programming (music)

Programming is a form of music production and performance using electronic devices, such as sequencers, to generate sounds of musical instruments. Programming is used in nearly all forms of electronic music and in most hip hop music since the 1990s. It is also frequently used in modern pop and rap rock music from various regions of the world, and sometimes in jazz and contemporary classical music. In the 21st century, programming has been incorporated into various styles of screamo and metalcore music known as crunkcore and electronicore respectively.

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Computer

A computer is a general purpose device that can be programmed to carry out a set of arithmetic or logical operations automatically. Since a sequence of operations can be readily changed, the computer can solve more than one kind of problem.

Conventionally, a computer consists of at least one processing element, typically a central processing unit (CPU), and some form of memory. The processing element carries out arithmetic and logic operations, and a sequencing and control unit can change the order of operations in response to stored information. Peripheral devices allow information to be retrieved from an external source, and the result of operations saved and retrieved.

Mechanical analog computers started appearing in the first century and were later used in the medieval era for astronomical calculations. In World War II, mechanical analog computers were used for specialized military applications such as calculating torpedo aiming. During this time the first electronic digital computers were developed. Originally they were the size of a large room, consuming as much power as several hundred modern personal computers (PCs).

Computer (disambiguation)

A computer is a program machine that receives input, stores and manipulates data, and provides output in a useful format.

Computer may also refer to:

Human computer

The term "computer", in use from the early 17th century (the first known written reference dates from 1613), meant "one who computes": a person performing mathematical calculations, before electronic computers became commercially available. "The human computer is supposed to be following fixed rules; he has no authority to deviate from them in any detail." (Turing, 1950) Teams of people were frequently used to undertake long and often tedious calculations; the work was divided so that this could be done in parallel.

The first time the term "Computer" appeared in The New York Times was February 3, 1853; an obituary stated:

Since the end of the 20th century, the term "human computer" has also been applied to individuals with prodigious powers of mental arithmetic, also known as mental calculators.

Origins in astronomy

The approach was taken for astronomical and other complex calculations. Perhaps the first example of organized human computing was by the Frenchman Alexis Claude Clairaut (1713–1765), when he divided the computation to determine timing of the return of Halley's Comet with two colleagues, Joseph Lalande and Nicole-Reine Lepaute.