What is C language

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C is a general-purpose, procedural programming language. Dennis Ritchie first devised C in the 1970s (at AT&T Bell Laboratories in Murray Hill, New Jersey) for the purpose of implementing the Unix operating system and utilities with the greatest possible degree of independence from specific hardware platforms. The key characteristics of the C language are the qualities that made it suitable for that purpose:
  • Source code portability
  • The ability to operate “close to the machine”
  • Efficiency
  • As a result, the developers of Unix were able to write most of the operating system in C, leaving only a minimum of system-specific hardware manipulation to be coded in assembly.
    Because C was expressly designed for system programming, it is hardly surprising that one of its major uses today is in programming embedded systems. At the same time, however, many developers use C as a portable, structured high-level language to write programs such as powerful word processor, database, and graphics applications.

    History of C

    Here we are discussing brief history of c language. It was developed to supersede the drawback of previous languages such as B, BCPL etc.
    Initially, C language was developed to be used in UNIX operating system. It inherits many features of previous languages such as B and BCPL.
    Let's see the programming languages that were developed before C language.

    LanguageYearDeveloped By
    Algol1960International Group
    BCPL1967Martin Richard
    B1970Ken Thompson
    Traditional C1972Dennis Ritchie
    K & R C1978Kernighan & Dennis Ritchie
    ANSI C1989ANSI Committee

    Features of C

    C is the widely used language. It provides a rich setfeatures that are given below.

  • Simple
  • Machine Independent or Portable
  • Mid-level programming language
  • structured programming language
  • Rich Library
  • Memory Management
  • Fast Speed
  • Pointers
  • Recursion
  • Extensible
  • First C Program

    Every C program must define at least one function of its own, with the special name main( ): this is the first function invoked when the program starts. The main( ) function is the program’s top level of control, and can call other functions as subroutines.
    Example for first C Program.

    #include <stdio.h>
    int  main( )
    printf("Hello World\n");
     return 0;
    Hello World
    Program Description
    #include <stdio.h>
  • It is the preprocessor command. It is the first statement of the program.
  • It starts with a hash (#) symbol.
  • The #include will tell the compiler to include the standard input/output library file (stdio.h).
  • int main()
  • main is first funtion of any c program and return value is int.
  • { }
  • The curly brackets are used to put together block of statements called body of function.
  • printf(“ Hello World\n”);
  • The printf function is already defined in the stdio.h file.
  • It is used for printing the text on console.
  • '\n' is an escape character which represents a newline character.
  • return 0;
  • returns 0 indicates sucessfrul termination of function.