/* example with chars and C-style strings
 */

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

int main ()
{
  char str1 [16] = "012345678901234";
  char str2 [16] = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 
                    'i', 'j', 'k', 'l', 'm', 'n', 'o', '\0'};
  char * str3 = str1;

  printf ("initialization\n");
  printf ("   str1:  %s\n", str1);
  printf ("   str2:  %s\n", str2);
  printf ("   str3:  %s\n\n", str3);
  printf ("integer values of variables\n");
  printf ("   str1:  %ld\n", str1);
  printf ("   str2:  %ld\n", str2);
  printf ("   str3:  %ld\n\n", str3);
  printf ("addresses of variables\n");
  printf ("   str1:  %ld\n", &str1);
  printf ("   str2:  %ld\n", &str2);
  printf ("   str3:  %ld\n\n", &str3);
  
  printf ("changing str1[3], str2[6], and str3[9]\n");
  str1[3] = 'X';
  str2[6] = 'Y';
  str3[9] = 'Z';
  printf ("   str1:  %s\n", str1);
  printf ("   str2:  %s\n", str2);
  printf ("   str3:  %s\n\n", str3);

  printf ("changing str3 reference\n");
  str3 = str2;
  printf ("   str1:  %s\n", str1);
  printf ("   str2:  %s\n", str2);
  printf ("   str3:  %s\n\n", str3);

  printf ("overwriting end of str1\n");
  str1[15] = 'Q';
  printf ("   str1:  %s\n\n", str1);

  printf ("overwriting end of str2\n");
  str2[15] = 'R';
  printf ("   str2:  %s\n\n", str2);

  printf ("initialization and pointer to constant string\n");
  char str4 [16] = "hello";
  char * str5    = "hello";
  printf ("   str4:  %s\n", str4);
  printf ("   str5:  %s\n\n", str5);

  printf ("accessing individual characters\n");
  int i;
  for (i = 0; i < strlen(str4); i++)
    printf (" '%c' ", str4[i]);
  printf ("\n");

  for (i = 0; i < strlen(str5); i++)
    printf (" '%c' ", str5[i]);
  printf ("\n");

  
  printf ("changing individual characters to upper case\n");
  for (i = 0; i < strlen(str4); i++)
    str4[i] = toupper(str4[i]);
  printf ("   str4:  %s\n", str4);

  str5[0] = 'H';
  printf ("   str5:  %s\n", str5);

  return 0;
}