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Definition: C


(1) See coulomb.

(2) A high-level programming language developed at Bell Labs that is also able to manipulate the computer at a low level like assembly language. Developed in the 1970s, by the end of the 1980s, C became the language of choice for developing commercial software. There are C/C++ compilers for all major platforms. C, and its object-oriented successor C++, are used to write a huge variety of applications and many operating systems. In 1989, C was standardized by ANSI (X3J11 committee) and ISO.

C++ (C Plus Plus)
Created by Bjarne Stroustrup in 1983, C++ added object-oriented programming (OOP) to C. Originally called "C with Classes," C++ became the standard C language, often designated as C/C++. In contrast, Smalltalk and other object-oriented languages did not provide the familiar structures of conventional languages such as C and Pascal. See object-oriented programming, Smalltalk, Visual C++, Objective-C, C# and Managed C++.

Nothing But Functions
C and C++ are written as a series of functions that call each other for processing. Even the body of the program is a function named "main." Functions are very flexible, allowing programmers to choose from the standard library or write their own, which they do in every program. They can also use third-party libraries for specific purposes. See function.

Its Origin
C was developed to allow Unix to run on a variety of computers. After Bell Labs' Ken Thompson and Dennis Ritchie created Unix and got it running on several PDP computers, they wanted a way to easily port it to other machines without having to rewrite it from scratch. Thompson created the B language, which was a simpler version of the BCPL language, itself a version of CPL. Later, in order to improve B, Thompson and Ritchie created C.

The following examples convert Fahrenheit to centigrade in C and C++. For another example of C code, see event loop.

 In C

 main()   {
  float fahr;
  printf("Enter Fahrenheit: ");
  scanf("%f", &fahr);
  printf("Celsius is %f\n", (fahr-32)*5/9);
          }


 In C++

 void main() {
  float fahr;
  cout << "Enter Fahrenheit: "; 
  cin >> fahr;
  fahr = (((fahr-32)*5)/9);
  cout << "Celsius = " << fahr << endl;
  return 0;
             }