// str2.cpp		By: Aiman Hanna -  ©1993-2006 Aiman Hanna
//
// The C-Style character string (char*) originated with the C language and continues
// to be supported by C++ (see str1.h & str1.cpp for full details). In fact, until 
// Standard C++, it was the only string support available. 
// Standard C++ provided a common implementation of a string class abstraction. 
//
// The C++ string type provides various functionality including:
// - Initialization of a string with another string (not supported by the C-style string),
// - Copy strings (strcpy with C-Style)
// - Access individual character in a string (can be done through pointer traversal with C-Style)
// - String comparisons (strcmp with C-Style)
// - Appending of strings (strcat & strncat with C-Style)
// - Character count in a string (strlen with C-Style)
//
// - Detection if a string is empty (with C-Style, this can be done through: if (!str || !*str) {….} )
//
// This program illustrates some of these C++ string type operations. It should be 
// noted however that string implementation by the standard library actually provides 
// a great deal more than this functionality. 
//
// The Standard C++ generic algorithms can also be used with the string type. 
//
//		Key Points: 1) Standard C++ string type 
//			    2) Standard C++ generic algorithms 


#include <string>
#include <iostream>
#include <algorithm>

using namespace std;

int main()
{
	string s1 ("Greeting from STL \n The Standard Template Library.");
	
	string s2 = "Hello ", s3 = "there.", s4;	// s4 is an empty string
	
	cout << "The size (length) of s1 is: " << s1.size();
	cout << "\nNotice that the \\n character is counted; the \\0 character is not. \n"; 


	if (s4.empty())
	{
		cout << "\ns4 is empty; will perform some string operations.\n";

		s2 += s3;
		s4 = s2;

		cout << "\ns2 now is: " << s2 << "\ns3 now is: " << s3 
			 << "\nand s4 now is: " << s4 << endl;

		cout << "\nModifying s2 and s4; will they affect each others? \n";

		replace(s2.begin(), s2.end(), 'e', 'x');	//.replace is from the generic algorithms; 
		replace(s4.begin(), s4.end(), 'e', 'o');	// it is not part of the string type

		cout << "\ns2 now is: " << s2 << "\nand s4 now is: " << s4 << endl;

	}
	cout << endl;
	return 0;
}

/* The output
The size (length) of s1 is: 50
Notice that the \n character is counted; the \0 character is not.

s4 is empty; will perform some string operations.

s2 now is: Hello there.
s3 now is: there.
and s4 now is: Hello there.

Modifying s2 and s4; will they affect each others?

s2 now is: Hxllo thxrx.
and s4 now is: Hollo thoro.


*/