/*
 * pointers.c
 *
 * An example of strings and pointers that we did in class Nov 10 2020.
 *
 *     $ make pointers
 *     cc pointers.c -o pointers
 *     $ ./pointers
 *      a is 'gi!dbye'
 *      p is 'hi!lo'
 *      p[1] is 'i'
 *      q[2] is 'n'
 *
 *
 * Jim Mahoney | cs.bennington.college 
 */

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

int main(){

  char a[10];   // This is a declaration of a block of memoery.

  //       a[0]  0x1234      'h'
  //       a[1]  0x1235      'i'
  
  char* p = malloc(10);      // This declares a pointer ... to some memory.
  
  char* q = "Bond. James Bond.";

  strcpy(p, "hello");    // put string "hello" into p
  strcpy(a, "goodbye");  // similar for a
  
  *(a+1) = 'i';   // one way to put 'i' at a[0]
  a[2] = '!';     // SAME!

  *(p+1) = 'i';   // put 'i' at p[1]
  p[2] = '!';

  printf(" a is '%s' \n", a);  // address of a[0]
  printf(" p is '%s' \n", p);  // p is address of p[0]

  printf(" p[1] is '%c' \n", p[1]); 

  printf(" q[2] is '%c' \n", q[2]);
  
  return 0;
}