Design and test a C program to demonstrate storage classes

Code

// A C program to demonstrate different storage
// classes
#include <stdio.h>

// declaring the variable which is to be made extern
// an initial value can also be initialized to x
int x;

void autoStorageClass()
{

    printf("\nDemonstrating auto class\n\n");

    // declaring an auto variable (simply
    // writing "int a=32;" works as well)
    auto int a = 32;

    // printing the auto variable 'a'
    printf("Value of the variable 'a'"
           " declared as auto: %d\n",
           a);

    printf("--------------------------------");
}

void registerStorageClass()
{

    printf("\nDemonstrating register class\n\n");

    // declaring a register variable
    register char b = 'G';

    // printing the register variable 'b'
    printf("Value of the variable 'b'"
           " declared as register: %d\n",
           b);

    printf("--------------------------------");
}

void externStorageClass()
{

    printf("\nDemonstrating extern class\n\n");

    // telling the compiler that the variable
    // x is an extern variable and has been
    // defined elsewhere (above the main
    // function)
    extern int x;

    // printing the extern variables 'x'
    printf("Value of the variable 'x'"
           " declared as extern: %d\n",
           x);

    // value of extern variable x modified
    x = 2;

    // printing the modified values of
    // extern variables 'x'
    printf("Modified value of the variable 'x'"
           " declared as extern: %d\n",
           x);

    printf("--------------------------------");
}

void staticStorageClass()
{
    int i = 0;

    printf("\nDemonstrating static class\n\n");

    // using a static variable 'y'
    printf("Declaring 'y' as static inside the loop.\n"
           "But this declaration will occur only"
           " once as 'y' is static.\n"
           "If not, then every time the value of 'y' "
           "will be the declared value 5"
           " as in the case of variable 'p'\n");

    printf("\nLoop started:\n");

    for (i = 1; i < 5; i++)
    {

        // Declaring the static variable 'y'
        static int y = 5;

        // Declare a non-static variable 'p'
        int p = 10;

        // Incrementing the value of y and p by 1
        y++;
        p++;

        // printing value of y at each iteration
        printf("\nThe value of 'y', "
               "declared as static, in %d "
               "iteration is %d\n",
               i, y);

        // printing value of p at each iteration
        printf("The value of non-static variable 'p', "
               "in %d iteration is %d\n",
               i, p);
    }

    printf("\nLoop ended:\n");

    printf("--------------------------------");
}

int main()
{

    printf("A program to demonstrate"
           " Storage Classes in C\n\n");

    // To demonstrate auto Storage Class
    autoStorageClass();

    // To demonstrate register Storage Class
    registerStorageClass();

    // To demonstrate extern Storage Class
    externStorageClass();

    // To demonstrate static Storage Class
    staticStorageClass();

    // exiting
    printf("\n\nStorage Classes demonstrated\n");

    return 0;
}

Output




big output i know but try to understand by doing :)