SECTIONS IN C

SECTION IN C

In C programming language, a program can be divided into several sections to organize the code and make it more readable and manageable. The main sections in a C program are:

Preprocessor Directives:

This section contains statements that are processed by the preprocessor before the compilation of the code. It typically includes include statements to import other header files and define statements to declare constants.

Syntax:

#include <header_file.h> // Preprocessor directive to include a header file

#define CONSTANT value   // Define a constant

Global Declarations:

This section contains the declaration of global variables and functions that are used throughout the program.

Syntax: 

data_type variable_name;      // Declare a global variable.

return_type function_name(); // Declare a global function.

Main Function:

This section is the starting point of the program where the code execution begins. It typically contains the main logic of the program.

Syntax: 

int main () 

{

    // Code statements

    return 0;

}

Functions:

This section contains definitions of user-defined functions that are called from the main function or other functions.

Syntax:

return_type function_name(parameters)

{

    // Code statements

    return value;  // Return a value.

}

Libraries:

This section contains the declarations for external libraries that the program uses. These libraries are typically included through preprocessor directives.

Syntax:

#include <library.h>   // Preprocessor directive to include a library

Comments:

This section is used to document the code and explain its functionality. Comments are not executed by the compiler.

Syntax:

// This is a single-line comment

/* This is a multi-line comment */

Here is an example C program showing how these sections are organized:

#include <stdio.h>        // Preprocessor directive to include a header file

int global_var = 10;      // Global declaration of a variable

void function_name();     // Global declaration of a function

int main() 

{              // Main function

    // Code statements

    function_name();      // Call to the function

    return 0;

}

void function_name() {    // Function definition

    // Code statements

}