In this article, we are going to learn about the basic structure of a C program. A C program is divided into different sections. There are six main sections to a basic c program.
The six sections are,
So now that the introduction is out of the way, let us jump to the main discussion. The whole code follows this outline. Each code has a similar outline. Now let us learn about each of these layers in detail.
The documentation section is the part of the program where the programmer gives the details associated with the program. He usually gives the name of the program, the details of the author and other details like the time of coding and description. It gives anyone reading the code an overview of the code.
Example
/**
* File Name: Helloworld.c
* Author: Manthan Naik
* date: 09/08/2019
* description: a program to display hello world
* no input needed
*/
Moving on to the next bit of this basic structure of a C program article,
This part of the code is used to declare all the header files that will be used in the program. This leads to the compiler being told to link the header files to the system libraries.
Example
| #include<stdio.h> |
In this section, we define different constants. The keyword define is used in this part.
| #define PI=3.14 |
This part of the code is the part where the global variables are declared. All the global variables used are declared in this part. The user-defined functions are also declared in this part of the code.
| float area(float r); int a=7; |
Every C-program needs to have the main function. Each main function contains 2 parts. A declaration part and an Execution part. The declaration part is the part where all the variables are declared. The execution part begins with the curly brackets and ends with the curly close bracket. Both the declaration and execution parts are inside the curly braces.
Example:
| int main(void) { int a=10; printf(” %d”, a); return 0; } |
All the user-defined functions are defined in this section of the program.
Example:
| int add(int a, int b) { return a+b; } |