Structure of C program

/* This program prints Hello World on screen */

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

#include <stdio.h>

Void main()

{

   printf(''Hello World\n'');

}

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

•  /* This program ... */

The symbols /* and */ used for comment. This Comments are ignored by the compiler, and are used to provide useful information about program to humans who use it.

• #include<stdio.h>

This is a pre-processor command which tells compiler to include stdio.h file.

•  main()

C programs consist of one or more functions. There must be one and only one function called main. The brackets following the word main indicate that it is a function and not a variable.

• { }

braces surround the body of the function, which may have one or more instructions/statements.

• printf()

it is a library function that is used to print data on the user screen.

• ''Hello World\n'' 

It is a string that will be displayed on user screen \n is the newline character.

• ;

 A semicolon ends a statement.

• return 0;

 return the value zero to the Operating system.


C is case sensitive language, so the names of the functions must be typed in lower case as above.

we can use white spaces, tabs & new line characters to make our code easy to read.