How do I delete an instance of an Array?

[moznmar]

I apologize, but I meant to make the below post in the C/C++ forum. I'm not sure how I may move it to the other forum or delete it and repost it in the correct forum. I would appreciate any guidance on how to correct my mistake. Thank you.

I'm using an array of class instances to store an inventory of a book store program I'm writing for school. Upon selling a book, I would like to have the instance storing the data on the sold book deleted out so that the book won't show the next time I display the inventory. I've been working on this for a while, but seem to be stuck. Any ideas? Here is the code I've written so far.

#include <iostream>
#include <iomanip>
#include <string>
#define MAX 100						//Maximum number of books in inventory array

using namespace std;

class CBooks						//Class definition
{
public:

	//Constructor
	CBooks(){string m_bookName; string m_author; string m_isbn;}

	//Destructor
	~CBooks(){};	

	//Functions
	void inputBooks(void);
	void displayBooks(void);
	void getProfit(void);
	void viewProfit(void);

private:
	string m_bookName;				//Name of book
	string m_author;				//Author of book
	string m_isbn;					//ISBN of book
	float m_price;					//Price of book
	float m_profit;					//Profit of book sale
	float m_totalProfit;			//Total of all profits
	int m_choice;					//Number of book chosen for purchase
}inventory[MAX];					//Array of class objects

//Global variables
int current;						//Used to count number of books in inventory

//Main Function
int main()
{
	//Declare variables
	int x = 0, transaction, another = 2;
	string password; 

	while (another != 1)
		{
			system("CLS");
			//display section header
			cout << "***********************\n";
			cout << "*Team A Book Inventory*\n";
			cout << "***********************\n\n";

			cout << "Please type the number of the desired action and press <ENTER>:\n" ;
			cout << "1. Buy\n";
			cout << "2. Sell\n";
			cout << "3. View Profit\n";
			cin	 >> transaction;
			cin.ignore();	//statement is necessary in order to make cin.getline() to work properly. 
							//Tells cin to ignore the line feed at the end of input

			//code to view profit
			if (transaction == 3)
			{
				inventory[x].viewProfit();
			}		
			// code to sell a textbook
			if (transaction == 2)
			{	
				if (x<=99)
				{
					system("CLS");
					//display section header
					cout << "***********\n";
					cout << "*Sell Book*\n";
					cout << "***********\n\n";

					inventory[x].inputBooks();
					x++;
				}
				else
				{
					cout << "I'm sorry, the database cannot hold any more books.\n";	//print if more then 100 books in inventory
				}
			}
			//code to buy book
			if (transaction == 1)	
			{	
				system("CLS");	//clear screen
				//display section header
				cout << "**********\n";
				cout << "*Buy Book*\n";
				cout << "**********\n\n";

				cout << "Book Name    " << "Book Author    " << "ISBN    " << "Price\n";	//print buy header
				cout << "---------    " << "-----------    " << "----    " << "-----\n\n";	//print buy header
				inventory[x].displayBooks();
			}
			cout << "\nPlease type the number of the desired action and press <ENTER>:\n";	//print option make another trans
			cout << "1. Quit program\n";													//quit program
			cout << "2. Make another transaction\n";										//make another trans
			cin >> another;																	//get answer

			if (another == 1)	//check if user selected exit
			{
				cout << "WARNING!! Data will be lost if program is exited. Are you sure you want to exit?\n";	//print warning about loosing data
				cout << "1. Yes, please exit.\n";
				cout << "2. No, stay in program.\n";
				cin >> another;		//get answer again
			}
		}

	return 0;
}

//Input books into inventory function
void CBooks::inputBooks(void)
{
	cout << "Please enter the book's name: \n";
	getline(cin, m_bookName);
	cout << "Please enter the book's author: \n";
	getline(cin, m_author);
	cout << "Please enter the book's ISBN: \n";
	getline(cin, m_isbn);
	cout << "Please enter the desired price: \n";
	cin >> m_price;
	cin.ignore();

	//Increments the number of books entered into inventory
    current++;
	cout << "\nThere are now " << current << " books for in our inventory.\n";
}

//Diplay books in inventory function
void CBooks::displayBooks(void)
{
	int loop;
	
	for (loop = 0; loop < current; loop++)
	{
		cout << inventory[loop].m_bookName << "   ";
		cout << inventory[loop].m_author << "   ";
		cout << inventory[loop].m_isbn << "   ";
		cout << inventory[loop].m_price << "\n";
	}
	cout << "\nPlease enter the number of the book you would like to buy:\n";
	cin >> m_choice;	//the number choosen
	cout << "Thank you for your purchase!\n\n";

	//Calculates 10% profit and updates total profit
	m_profit = inventory[m_choice - 1].m_price * .10;
	m_totalProfit += m_profit;
}

//Checks password and diplays profit
void CBooks::viewProfit()
{
	string password;

	system("CLS");
	//display header section
	cout << "*************\n";
	cout << "*View Profit*\n";
	cout << "*************\n\n";

	cout << "Please type your password:\n";
	cin >> password;
	if (password == "upwd") //check password
	{
		cout << "Profit = $" << fixed << showpoint << setprecision(2) 
			 << m_totalProfit << "\n";
	}
	else 
	{
		cout << "Invalid password.\n";
		}
	system("PAUSE");
}

[Narue]

>I'm not sure how I may move it to the other forum
Done. In the future, you can either delete your thread with the thread tools provided nobody has posted a reply, or you can contact a moderator with admin powers on both the to and from forum (such as myself) and they can move it for you.

>Any ideas?
Rather than storing objects, store pointers to objects so that a non-existent book can be a null pointer. Alternatively, use an std::list to store the books so that they can be easily removed when needed. I wouldn't recommend an array because it's just too awkward to delete items from anywhere except the end.

[moznmar]

Narue,

I appreciate you moving the post for me. I must use an array, because that is what my professor told us to use for this program. I'll try the pointers. Thanks.

[cscgal]

>In the future, you can either delete your thread with the thread tools provided nobody has posted a reply

I actually don't believe that members have the ability to delete threads.