A C program is organized into declarations, definitions, statements, and functions. The main() function serves as the entry point of a hosted C program.

#include <stdio.h>

int add(int a, int b)
{
    return a + b;
}

int main()
{
    int result = add(10, 20);

    printf("%d\n", result);

    return 0;
}

Example Output #

30

Explanation #

The program contains several structural elements.

#include <stdio.h>

The preprocessor directive includes the standard I/O header so that printf() can be used.

int add(int a, int b)
{
    return a + b;
}

This defines a function named add. It accepts two int parameters and returns an int.

int main()

defines the program’s main function.

{
    int result = add(10, 20);

    printf("%d\n", result);

    return 0;
}

The braces define the body of main. The statements inside the body execute when main is called as the program’s entry point.

Basic C Program Elements #

A C source file can contain multiple functions, declarations, definitions, and preprocessor directives. The exact organization depends on the program, but execution in a hosted environment begins with main().