Structure of C Program

The basic Structure of C Program is as follow:

Document Section

Links Section (File)

Definition Section

Global variable declaration Section

voidmain ()

{
    Variable declaration section
    Function declaration section
    executable statements;
}

voidmain (): Used to start of actual C program. It includes two parts as declaration part and executable part.

Variable declaration section: Used to declare private 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().

C Basic Program

#include<stdio.h>

#include<conio.h>

void main()

{

 printf("Welcome to SOLMEYVN…");

}

Difference between Compiler and Interpreter

The main difference between Compiler and Interpreter is:

Compiler translates the program statements(Source Code) into Machine Code in one go i.e. all lines of program simultaneously. That's why all compiler based languages shows all the errors together.

While interpreter translates the source code into machine code one statement at a time. That's why program execution cannot proceed to next statement until the previous error is corrected/rectified.

Different parts of C program

1.       Pre-processor   

2.       Function

3.       Variables

4.       expression

5.       Comment

Pre-processor: #include < file name>

The first word of any C program. It is also known as pre-processor. The main work of pre-processor is to initialize the environment of program, i.e to link the program with the header file.

Example : #include<stdio.h>

#include- Inclusion Directive

<  > è  Search file only local  file system 

Std- standard

Ièinput

Oèoutput

Main function: main() function is a function that must be used in every C program. A function is a sequence of statement required to perform a specific task. main() function starts the execution of C program. In the above example, int in front of main() function is the return type of main() function. we will discuss about it in detail later. The curly braces { } just after the main() function encloses the body of main() function.

Input output function:

scanf() and printf() functions