/*
 *          File: String-test2.cpp
 *        Author: Robert I. Pitts <rip@cs.bu.edu>
 * Last Modified: December 1, 1999
 *         Topic: A String Class: Part II - Lab
 * ----------------------------------------------------------------
 *
 * This program demonstrates a basic String class that implements
 * dynamic allocation and operator overloading.
 *
 */


#include <iostream.h>
#include "mystring.h"


/************************ Function Prototypes ************************/

/*
 * Function: PrintString
 * Usage: PrintString(str);
 *
 * Prints out the value and length of the String object passed to it.
 */
void PrintString(const char *label,
                 const String &str);

/*
 * Function: TestCopy
 * Usage: TestCopy(copy_str);
 *
 * Accepts a copy of a string (i.e., by value) to make sure the copy
 * constructor does what it is supposed to.
 */
void TestCopy(String copy_str);

/*************************** Main Program **************************/

int main()
{
  String str1, str2("init2"), str3 = "init3";  // Some String objects.
  char s1[100], s2[100], s3[100];              // Some character strings.

  // Print out their initial values...

  cout << "Initial values:" << endl;
  PrintString("str1", str1);
  PrintString("str2", str2);
  PrintString("str3", str3);

  // Store some values in them...

  cout << "\nEnter a value for str1 (no spaces): ";
  cin >> s1;
  str1 = s1;

  cout << "\nEnter a value for str2 (no spaces): ";
  cin >> s2;
  str2 = s2;

  cout << "\nEnter a value for str3 (no spaces): ";
  cin >> s3;
  str3 = s3;

  cout << "\nAfter assignments..." << endl;
  PrintString("str1", str1);
  PrintString("str2", str2);
  PrintString("str3", str3);

  // Access some elements...

  int i;

  cout << "\nEnter which element of str1 to display: ";
  cin >> i;
  cout << "Element #" << i << " of str1 is '" << str1[i]
       << "'" << endl;

  cout << "\nEnter which element of str2 to display: ";
  cin >> i;
  cout << "Element #" << i << " of str2 is '" << str2[i]
       << "'" << endl;

  cout << "\nEnter which element of str3 to display: ";
  cin >> i;
  cout << "Element #" << i << " of str3 is '" << str3[i]
       << "'" << endl;

  // Append some strings...

  cout << "\nEnter a value to append to str1 (no spaces): ";
  cin >> s1;
  str1.append(s1);

  cout << "\nEnter a value to append to str2 (no spaces): ";
  cin >> s2;
  str2.append(s2);

  cout << "\nEnter a value to append to str3 (no spaces): ";
  cin >> s3;
  str3.append(s3);

  cout << "\nAfter appending..." << endl;
  PrintString("str1", str1);
  PrintString("str2", str2);
  PrintString("str3", str3);

  // Compare some strings...

  cout << "\nComparing str1 and str2..." << endl;

  cout << "\"";
  str1.print();
  cout << "\" is ";

  if (str1 < str2) {
    cout << "less than";
  } else if (str1 > str2) {
    cout << "greater than";
  } else {
    cout << "equal to";
  }

  cout << " \"";
  str2.print();
  cout << "\"" << endl;

  // Demonstrate the copy constructor.

  cout << "\nDemonstrating copy constructor..." << endl;

  String str4 = "original value";

  cout << "Before call by value: ";
  PrintString("str4", str4);
  TestCopy(str4);
  cout << "After call by value: ";
  PrintString("str4", str4);

  return 0;
}


/*********************** Function Definitions **********************/

void PrintString(const char *label,
                 const String &str)
{
  cout << label << " holds \"";
  str.print();
  cout << "\" (length = " << str.length() << ")" << endl;
}

void TestCopy(String copy_str)
{
  // Change copy, leaving original alone.
  copy_str = "new value";
  PrintString("copy_str", copy_str);
}