/*
   usingptrs.c - demonstrates using C pointers

   For CS 60 assignment 2, part 1, Fall 2009:
       Run AS-IS and explain the output (see instructions).   

   updated by cmc, 10/6/09
*/

#include <stdio.h>
#include <stdlib.h>

int main(void) {

    char cval, *cptr;
    int ival, *iptr;
    double dval, *dptr;

/*
  a. Using a pointer to char
*/
    cval = 'K';
    cptr = &cval;
    printf("\na. %c (actually %d) @ %p\n", *cptr, cval, cptr);

/*
  b. Using pointers to int and double
*/
    ival = cval;
    iptr = &ival;
    dptr = &dval; /* notice how dval assigned */
    *dptr = *iptr;
    printf("\nb. %d @ %p, and %.1f @ %p\n", ival, iptr, dval, dptr);

/*
  c. Using sizeof operator for char, int and double values
*/
    printf("\nc. bytes @ %p, %p and %p are %d, %d and %d\n",
            cptr, iptr, dptr, sizeof cval, sizeof ival, sizeof dval);

/*
  d. Using sizeof operator for pointers
*/
    printf("\nd. %p @ %p in %d bytes, and %p @ %p in %d bytes\n",
           cptr, &cptr, sizeof cptr, dptr, &dptr, sizeof dptr);

/*
  e. Using a pointer for dynamic memory allocation and use
*/
    iptr = malloc(sizeof(int) * 10);
    for (ival = 0; ival < 10; ival++)
        *(iptr + ival) = ival * 10;
    printf("\ne.  value\t@\n");
    for (ival = 0; ival < 10; ival++)
        printf("%8d\t%p\n", iptr[ival], iptr + ival);

    free(iptr);
    return 0;
}