//-----------------------------------------------------------------
// Author:	Zhixiang Chen
// Class:	CSCI/CMPE 2380, Spring 2009
// Lab 6:	Virtual methods vs. polymorphism
// Date:	January 14, 2009
// Comment: The code here is meant to be revised.
//
//-----------------------------------------------------------------
//
// This lab exercise is practice virtual methods vs. polymorphism
//
// Compile and run your program. When everything is fine,
// print your .cpp and .h files and turn them to me or the TA.
// *****************************************************************

#include < iostream >
#include < fstream >
#include < string >
#include < cstring >
#include < cmath > 
#include < cstdlib >
#include < iomanip >
#include < vector >

#include "lab2380_6_head.h" 

using namespace std; 

int main()
{	
	/************************************************************
	 Part One: Watch the output. Try to understand: 
			   No virtual methods, no polymorphism.
	 ************************************************************/
	One dog; 
	Two cat; 
	Three rat;
 
	One * objPtr[3];					//base class pointer
	objPtr[0]=&dog;						//normal binding to a base class object
	objPtr[1]=&cat;						//dynamic binding to a derived class object
	objPtr[2]=&rat;						//dynamic binding to a derived class object

	for(int i=0; i<3; i++)
		objPtr[i]->whoami();			//no virtual function, no polymorphism.
	
	cout<<" This is the end of Part one." <<endl<<endl; 

	/************************************************************
	 Part Two: Watch the output. Try to understand:
			   Virtual methods vs. polymorphism.
	 ************************************************************/
	MyOne myDog;						
	MyTwo myCat; 
	MyThree myRat;
 
	MyOne * myObjPtr[3];				//base class pointer	
	myObjPtr[0]=&myDog;					//normal binding to a base class object
	myObjPtr[1]=&myCat;					//dynamic binding to a derived class object
	myObjPtr[2]=&myRat;					//dynamic binding to a derived class object

	for(int i=0; i<3; i++)
		myObjPtr[i]->whoami();			//polymorphism is realized via virtual functions
	
	cout<<" This is the end of Part Two." <<endl<<endl; 

	/************************************************************************************
	  Part Three: Now you shall play with virtual methods vs. polymorphism:
		(1)	Define an abstract base class Write via defining a pure virtual  
			method 	void print().
		(2) Derive three classes MyWrite, YourWrite, HerWrite from the base
			class Write. 
			Redefine void print() in MyWrite to print "I like C++.". 
			Redefine void print() in YourWrite to print "You don't like C++.". 
			Redefine void print() in TheirWrite to print "They don't care about C++.". 
		(3) Use a base class Write pointer p and call p->print() to invoke different 
			definitions of print in MyWrite, YourWrite and TheirWrite. 
			That is, use the same call p->print() to realize different functionalities
			-- polymorphisam. 
	
	  How to submit this lab?
	  Turn in your code plus the written observations for option 3.

	  *************************************************************************************/

	


	//complete the program 
	return 0; 
}