Introduction To C Programming Language

Fundamental Of C

C was originally developed in 70's by DENNIS RITCHIE at Bell Telephone Laboratories Inc for the purpose of implementing the UNIX operating system. It is an outgrowth of two earlier languages, called BCPL and B.

C is a general-purpose programming language that is extremely popular, simple and flexible. It is machine-independent, structured programming language which is used extensively in various applications.

C was largely confined to use with bell laboratories until 1978, when Kernighan and Ritche published a definitive description of the language.

Numerous compilers had been written for computers of all sizes and many commercial applications had been developed . Most commercial implementations of c differed from Kernignhan and Ritchie's original definition.

It is a high-level programming language. However, often referred as a middle-level programming language; since it provides rich support to low-level programming constructs.

Features of C:

  • Structured language
  • Simple and Robust
  • Portable
  • Extensibility
  • Wide acceptability
  • It has Limited Number of Key Word
  • It can also handle low-level prograramming

Characteristics of C

All languages have a characteristic look. C has a variety of language characteristics that are largely a consequence of the original constricted development environment and its original applications implementation of an operating system. Some of the most significant characteristics of the languages are list below:

Size of Language :

C is an externally small language. C does not have any built-in input/output capabilities it contains no string handling function, and arithmetic operations beyond those such as basic addition or subtraction.

C provides this functionality through a rich set of function libraries. Most C implementations include standard libraries for input/output, string manipulations and arithmetic operations.

C is characterized by the ability to write concise source programs. C programs use an extensive usage of funcion calls. C programs are highly portable.

Applications of C

Mainly C Language is used for Developing Desktop applications and system softwares. Some application of C language are given below.

  • Operating Systems
  • Interpreters
  • Assembly Programs
  • Text Editors
  • Compilers
  • Utilities

Because of its portability and efficiency C is also used for variety of applications running under nearly all operating systems.

The C language is used for developing

  • Database systems.
  • Graphics Packages.
  • Spread sheets.
  • CAD/CAM Applications.
  • Word processors.
  • Office Automations.
  • Scientific and Engineering Applications

Because of its power, elegance, and portability, C will probably continue to flourish as preferred software development tool.

Simple Program In C

The main( ) function:

This is the function with which the operating system will start execution. Each and every C program must have one and only main( ) function, defined as follows.

   variable declaration;
   program statements;

variable Declarations:

All variables used in C language programs must declared. C variable declarations includes the name of the variable and its type.

Executable Statements:

executable statements must have variable declarations. An executable statement is an expression followed by semicolon or a control construct such as IF or an WHILE statement.