C-Programming Basics

“C Language “

Definition of Computer:-  A Computer is a electronic device that can performance a variety of operation in accordance with a set of instructions called program.

Difference between computer and calculator:- Using calculator we can perform only arithmetic operation where using computer we can perform arithmetic as well as logical operation.

O.S.:- (Operating System):- It is an interface between user and computer which makes computer comfortable   with user (means check all connected H/W) and provide interface (Eg. Promopt /desktop).

Note:- format =deleing the data + creation FAT.

FATàFile Allocation Table.

Software: - Dos, Windows, UNIX, Linux

Hardware: - BIOS (basic input output system).

Language: - it is a way of communication between two persons.

Computer Language: - it’s a way of communication between user and computer.

Programming language: - it is a special language with special symbol and instruction which is used to communicate with computer. It is also used for developing computer based application or software.      

There are three categories of computer language

·         Low level     :-  Assembly, machine(0,1)

·         Middle level: - C, C++.

·         High level    : - BASIC, COBOL, PASCAL, FORTRAN, JAVA, PL/SQL…..

High level programming language: - if any programming language synthetically similar to English and easy to understand called high level programming language.

Ø  By using high level programming language we can developed user interface applications

Low level programming language: -

In this programming language, we have to need of given instruction in symbol format and it is not easy to remember all instruction.

Ø  By using low level programming language we can develop system software components.

Ø  Low level programming language also called assembly language.

Note: C is also called system language.

            Window (95, 98, 2000, xp) O.S.

            Ms Office                        

            FoxPro                                 DBMS

            Visual FoxPro                      DBMS

            Oracle                                 RDBMS

            Sol server                            RDBMS

            Page maker 

            Coral draw

            VB, VC,

            Internet Explorer

Note:  All above this software are designed in “C”.    

Introduction of “C”:-

1)      “C” is a general purpose programming language.

2)      “C” is a middle level language programming language.

Ø  If any language reduce the gap between High level programming language &Low level programming language that is known as middle level programming language.

3)      “C” is a structure oriented programming language.

Ø  If any programming language design in top down approach with block format is called structure oriented programming language.

4)      “C” is a procedure oriented programming language.

Ø  Dividing an application in module format. These module formats are called procedure oriented programming language.

5)      “C” is a case sensitive programming language.

Ø  If any language define difference between upper case letter and lower case letter known as case sensitive programming language.

6)      “C” is a platform dependent programming language.

7)      “C” is a top down programming language.

8)      Every statement in “C” program should be ended or terminated with semicolon (;).

         

History of C Language:-

Year of Establishment	Language Name	Developed By
1960	ALGOL-60	Cambridge University
1963	CPL (Combined Programming Language)	Cambridge University
1967	BCPL (Basic Combined Programming Language)	Martin Richard at Cambridge University
1970	B	Ken Thompson at AT & T's Bell Laboratories.
1972	C	Dennis Ritchie at AT & T' Bell Laboratory.

The development of C was a cause of evolution of programming languages like Algol 60, CPL (Combined Programming Language), BCPL (Basic Combined Programming Language) and B.

·         Algol-60 : (1963) :

ALGOL is an acronym for Algorithmic Language. It was the first structured procedural programming language, developed in the late 1963s and once widely used in Europe. But it was too abstract and too general structured language.

·         CPL : (1963) :

CPL is an acronym for Combined Programming Language. It was developed at Cambridge University.

·         BCPL : (1967) :

BCPL is an acronym for Basic Combined Programming Language. It was developed by Martin Richards at Cambridge University in 1967. BCPL was not so powerful. So, it was failed.

·         B : (1970) :

B language was developed by Ken Thompson at AT & T Bell Laboratories in 1970. It was machine dependent. So, it leads to specific problems.

·         C : (1972) :

'C' Programming Language was developed by Dennis Ritchie at AT & T Bell Laboratories in 1972. This is general purpose, compiled, structured programming language. Dennis Ritchie studied the BCPL, then improved and named it as 'C' which is the second letter of BCPL

Syntax: - the grammar of any programming language is called syntax. It should be terminated with semicolon (;).                                

istory

Structure of C Program:-

The basic structure of C program is as follow:

Document Section

Links Section (File)

Definition Section

Global variable declaration Section

void main()

{
    Variable declaration section
    Function declaration section
    executable statements;
}

Function definition 1

---------------------

---------------------

Function definition n

Where,

Document Section: It consists of set of comment lines (*/  /*) which include name of a program, author name, creation date and other information.

Links Section (File):

Ø  It is used to link the required system libraries or header files to execute a program.

Ø  It established connection between “C” program to “C” libraries.

Syntax: - #include<header_file.h>

Ø  “C” library is collection of header files, every header files is collection of pre-define functions.

Ø  “C” library containing 27 header files with 400+ pre-define functions.

Ø  Header file mainly classified into two types.

1)      Pre-define header file.

2)      User define header file.

Ø  Pre –define header file is collection of pre define factions.

Ø  User define header file is collection of user define function.

Ø  # include is a pre-processor directive which can be used to include pre-define function of given header file into current “C” program before compilation.

Ø  One program contains any number of # include statements but it’s should be the first statement of “C” program.

void main() :

Ø  It is also known as main function or main block.

Ø  Used to start of actual C program. It includes two parts as declaration part and executable part.

Ø  Main function is a staring executive block of “C” program that means O.S will execute “C” program which are written inside the main () function and it neglects the statement which are written outside from the main() function.

Ø  Main () function is a heart of “C” program, without main () program can be compile but cannot be execute.

Syntax: -   main()

{

}

Ø  Return type represent what type of value the main () can able to return to the operating system. It can be any primitive data type or void.

Ø  One “C” program should be containing maximum one main ().

Variable declaration section: Used to declare variable.

Function declaration section: Used to declare functions of program from which we get required output.

Then, executable statements are placed for execution.

Function definition section: Used to define functions which are to be called from main ().

Note:- main() function is user define function but name is predefine.

Ø  Out of above sections link and main () sections are mandatory. And other sections are optional section.