Trouble with Pointers and Classes

[Rodekki]

Hey all. I'm new here and could use some help. I'm having a hard time finding out what's wrong with my code. It's the first time I've had to deal with pointers and have a hard time grasping how classes and objects work.

As of right now, it compiles, but proceeds to run together in a bad way.

I'm suppose to write a program that calls 3 objects, loads info into their data members and then prints out the information. There's also a function that let's you change the data that already exists in one of the objects if you choose too and another that displays total and average prices.

This is what I have so far (I've left the header files out.)

// Implementation file (.cpp) for class CDX

#include "CDX.h"
#include <iostream>
using namespace std;

CDX::CDX() //Constructor
{
	Sig = "No Sig";
	Type = "A";
	Price = 0.00;
};

void CDX::LoadInfo() //Prompts, validates and sets data members
{
	cout << "Enter CD Sig: ";
	getline(cin, Sig);

	int check=0;
	do
	{	cout << "1-A\n2-B\n3-C\n4-D\n5-E\n6-F" << endl;
		cout << "Enter the number that corresponds with the CD's Type: ";
		cin >> check;
	} while ((check <1)||(check>6));

	switch(check)
	{
	case 1: Type = "A";
		break;
	case 2: Type = "B";
		break;
	case 3: Type = "C";
		break;
	case 4: Type = "D";
		break;
	case 5: Type = "E";
		break;
	case 6: Type = "F";
		break;
	default:
		cout << "How in the world did you get here?!";
	}

	float newPrice;

	cout << "Input CD Price: ";
	cin >> newPrice;

	if ((newPrice > 0.0))
	{
		Price = newPrice;
	}
	else
	{
		cout << "Invalid amount entered - Price not changed.\n";
	}
};

float CDX::ReturnPrice() //return Price
{
	return Price;
};

void CDX::DisplayInfo() //Displays data members
{
	cout << "CD Sig: " << Sig << endl;
	cout << "CD Type: " << Type << endl;
	cout << "CD Price: " << Price << endl;
};

void CDX::ChangeData() //Changes existing data members
{
	char response;

	cout << "Current CD Sig: " << Sig << endl;
	cout << "Would you like to change the Sig? Enter Y or N: ";
	cin >> response;

	if ((response == 'Y')||(response == 'y'))
	{
		cout << "Please enter new CD Sig: " << endl;
		getline(cin, Sig);
	}
	else
	{
		cout << "Sig left unchanged." << endl;
	}

	cout << "Current CD Type:" << Type << endl;
	cout << "Would you like to change the type? Enter Y or N: ";
	cin >> response;

	if ((response == 'Y')||(response == 'y'))
	{
		int check=0;
		do
		{
		cout << "1-A\n2-B\n3-C\n4-D\n5-E\n6-F" << endl;
		cout << "Enter the number that corresponds with the CD's Type: ";
		cin >> check;

		} while ((check<1)||(check>6));

		switch(check)
		{
		case 1: Type = "A";
			break;
		case 2: Type = "B";
			break;
		case 3: Type = "C";
			break;
		case 4: Type = "D";
			break;
		case 5: Type = "E";
			break;
		case 6: Type = "F";
			break;
		default:
			cout << "You shouldn't be here.";
		}
	}
	else
	{
		cout << "CD Type unchanged." << endl;
	}

	cout << "Current CD Price: " << Price << endl;
	cout << "Would you like to change the Price? Y or N: " << endl;
	cin >> response;

	float cdPrice;

	if ((response == 'Y')||(response == 'y'))
	{
		cout << "Enter new Price: " << endl;
		cin >> cdPrice;
		if ((cdPrice > 0.00f))
		{
			Price = cdPrice;
		}
		else
		{
			cout << "Invalid amount entered - Price left unchanged." << endl;
		}
	}
	else
	{
		cout << "Price left unchanged." << endl;
	}
};

//Implementations for free functions 

#include "CDXFun.h"

#include <iostream>
using namespace std;

void ShowCDX(CDX *pCD1, CDX *pCD2, CDX *pCD3)
{
	if (pCD1 = 0)
	{
		pCD1 -> DisplayInfo();
	}
	else 
	{
		cout << "No information found." << endl;
	}

	if (pCD2 = 0)
	{
		pCD2 -> DisplayInfo();
	}
	else
	{
		cout << "No information found." << endl;
	}

	if (pCD3 = 0)
	{
		pCD3 -> DisplayInfo();
	}
	else
	{
		cout << "No information found." << endl;
	}
};


void ShowPrice(CDROM &CD1, CDROM &CD2, CDROM &CD3)
{
	float totalPrice;

	totalPrice = CD1.ReturnPrice()+CD2.ReturnPrice()+CD3.ReturnPrice();

	cout << "Total Price: " << totalPrice << endl;
	cout << "Average Price: " << (totalPrice/3) << endl;
};

void MemoryReturn(CDX *pCD1, CDX *pCD2,CDX *pCD3)
{
	delete pCD1;
	delete pCD2;
	delete pCD3;
};

//Main

#include "CDXFun.h"

#include <iostream>
#include <cstdlib>
#include <string>

using namespace std;


int main ()
{
	CDX *pCD1, *pCD2, *pCD3;

	pCD1 = new CDX;
		if ( 0 == pCD1)
		{
			cout << "Error: Dynamic Memory Allocation failed. Exiting.";
			exit(1);
		}

	pCD2 = new CDX;
		if ( 0 == pCD2 )
		{
			delete pCD1;
			cout << "Dynamic Memory Allocation failed. Exiting.";
			exit(1);
		}

	pCD3 = new CDX;
		if ( 0 == pCD3 )
		{
			delete pCD1;
			delete pCD2;
			cout << "Dynamic Memory Allocation failed. Exiting.";
			exit(1);
		}


	pCD1->LoadInfo();
	pCD2->LoadInfo();
	pCD3->LoadInfo();


	void DisplayCDS(CDX *pCD1, CDX *pCD2, CDX *pCD3);
	void ShowPrices(CDX &CD1, CDX &CD2, CDX &CD3);
	
	pCD1->ChangeData();
	pCD2->ChangeData();

	void DisplayCDS(CDX *pCD1, CDX *pCD2, CDX *pCD3);
	void ShowPrices(CDX &CD1, CDX &CD2, CDX &CD3);

	void MemoryReturn(CDX *pCD1, CDX *pCD2, CDX *pCD3);

return 0;

};

My problems:

- It skips the input parts for names on the second and third objects. (The first option on the menu's list goes appears there instead.)
- DisplayCDs isn't working (it just skips ahead to changing the data).
- ShowPrices doesn't work either.

It mostly runs, allowing me to put in some data, change it (still skips the name part) and then closes. I'm not really sure what I've done wrong.

PS: Please excuse any mismatching names. I changed them for the sake of posting and wouldn't be surprised if I messed them up.

[Rodekki]

I've figured out how to get my information to finally display, but I'm not sure if the data is still being passed as a pointer to the object.

DisplayCDS(pCD1, pCD2, pCD3);

Is this syntax a pass-by-value or am I still passing the objects as pointers?

The program is still skipping the input option for the second and third object names and failing to show the costs function.

[Rodekki]

Bumped