Storage.c

#include <stdio.h>

int x;

void autoStorageClass()
{

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

    auto int a = 32;

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

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

void registerStorageClass()
{

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

    register char b = 'G';

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

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

void externStorageClass()
{

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

    extern int x;

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

    x = 2;

    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");

    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++)
    {

        static int y = 5;

        int p = 10;

        y++;
        p++;

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

        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");

    autoStorageClass();

    registerStorageClass();

    externStorageClass();

    staticStorageClass();

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

    return 0;
}