BASIC STRUCTURE OF C PROGRAM

BASIC  STRUCTURE OF C PROGRAM

DOCUMENTATION SECTION

The documentation section  consist  of comments lines  giving  the name  of the program ,details  etc

PREPROCESSOR STATEMENTS

The  preprocessor  statements  begin with  #Symbol , which are  also  called pre processor directives.

These statements instruct the compiler to include preprocessor such as header files and symbolic constants before

Compiling the c program.

Ex .

#Include<Stdio.h>
#include<Conio.h>
#include<Math.h>
#Define P I 3.1412

GLOBAL DECLARATIONS

This variables are declared before the main() part of the function ,user defined functions  are also called global variables ,

Global variables can be accessed by all the user defined function including main() function .


main() FUNCTION

Every C program should contain only one main().

Execution of  C program starts with the main().

C is case sensitive and main() is written in lower case ,if you write in caps you will face the error.

The main() part of the program executes user defined functions,library function and user defined functions should be enclosed

With the left and right braces.

BRACES

Every C program should have  a pair of curly braces {  }

The left brace  ( { ) indicate the beginning of  the main() function .

Right brace ( } ) indicate the beginning of   the main() function.

LOCAL DECLARATIONS

The variable declaration is  part of C program ,all the variables declared are used in main() function are local variables .

We can also declare arrays,pointer ,function etc and the variable are initialised  with  the  basic data types .

main()
{
Int sum();

Int x;

Float Y;
}

PROGRAM STATEMENTS

These statements are building blocks of  C programs.

These statements  instructs to  perform specific task .

Statement are of different types like input  statement ,output statement,  control statements, assignment statement.

It also include comments  , comments are not executed  they are used just to understand   the program.


USER DEFINED FUNCTIONS

These  are sub programs,and  sub programs are  genrally defined as  user defined functions.

This functions  perform specific task  and also contains set  of  program statements.