Add objects to an array by reference?

[beebe]

I have 2 classes Business and Customer. Each Business holds an array of Customer objects m_curPatrons[], which represents the patrons of that particular business. I have a method that sells every member of that array an item, and increments Customer member variable m_purchases that shows how many items he's bought.

What's happening is the array m_curPatrons[] is a set of seperate objects outside of the original Customer objects, and Customers inside that array are getting their member variables modified. I'm wondering if I can construct the array so that the Customers in the array are indistinguishable from the original Customer objects. Code follows:

Header files

class Customer
{
private:
  string m_purchases[MAX_PURCH];
  short m_numPurchases; //how many purchases are held in m_purchases
  float m_money;
  string m_name;

public:
  // Constructors
  Customer();
  Customer(const string& name, const float& money);
  
  // Member Functions
  
  //Purpose: Add an item to the array of purchases
  //Post: item is either added to m_purchases[] or false is returned
  //Return: True if item successfully added, false otherwise
  bool purchase(const string& item);
  
  //Purpose: Modify the current amount of customer's money
  //Post: Either amt is added to m_money or False is returned
  //Return: True if successful, false if amt would reduce m_money below 0
  bool addMoney(const float& amt);

};

class Business
{
  private:
    string m_name;
    float m_till;
    string m_merchandise[MAX_MERCH];
    Customer m_curPatrons[MAX_PATRONS];
    short m_numPatrons;
    short m_numMerch;

  public:
    // Constructors
    Business() : m_name(""), m_till(0), m_numPatrons(0), m_numMerch(0) {};
    Business(const string& name, const float& till);

    // Member Functions

    //Purpose: Add a customer to the business's list of current patrons
    //Post: The customer to be added is appended to m_curPatrons or an error
    // message is printed
    void newPatron(const Customer& name);

    //Purpose: Sells random items from inventory to all current patrons
    //Post: Each patron who can afford an item is charged and are given
    // an item at random
    void make_a_sale();
};

Business Constructor

void Business::newPatron(const Customer& patron)
{
  if (m_numPatrons < MAX_PATRONS) //prevent exceeding size of m_curPatrons
  {
    m_curPatrons[m_numPatrons] = patron;
    m_numPatrons++;
    return;
  }
  else //print error message
  {
    cout << "Business " << m_name << " already full. " << patron.getName()
      << " was not added." << endl;
  }
}

void Business::make_a_sale()
{
  int randItem;
  for (int i=0; i<m_numPatrons; i++)
  {
    randItem = rand()%m_numMerch;
    // check if transaction can be completed before adding money to m_till
    if (m_curPatrons[i].purchase(m_merchandise[randItem]))
      m_till += COST;
  }
  
  return;
}

Functions

void Business::make_a_sale()
{
  int randItem;
  for (int i=0; i<m_numPatrons; i++)
  {
    randItem = rand()%m_numMerch;
    // check if transaction can be completed before adding money to m_till
    if (m_curPatrons[i].purchase(m_merchandise[randItem]))
      m_till += COST;
  }
  
  return;
}

bool Customer::purchase(const string& item)
{
  bool success = false;
  if (m_numPurchases < MAX_PURCH) //prevent purchasing too many items
  {
    if (addMoney(-COST)) //only do if the cost can be taken from m_money
    {
      m_purchases[m_numPurchases] = item;
      m_numPurchases++;
      success = true;
    }
  }
  return success;
}

bool Customer::addMoney(const float& amt)
{
  bool success = false;
  if (m_money+amt >= 0) //can't take more money than customer has
  {
    m_money += amt;
    success = true;
  }
  return success;
}

Right now when I call someBusiness.make_a_sale(), it'll increment m_numPurchases for each customer in someBusiness.m_curPatrons[]. But if someGuy is a Customer object that's been
added to that array, I want the the original someGuy.m_numPurchases to get incremented also.

Thank you for the help.

[xismn]

What's happening is the array m_curPatrons[] is a set of seperate objects outside of the original Customer objects, and Customers inside that array are getting their member variables modified. I'm wondering if I can construct the array so that the Customers in the array are indistinguishable from the original Customer objects.

But if someGuy is a Customer object that's been
added to that array, I want the the original someGuy.m_numPurchases to get incremented also.

What exactly do you mean? Elaborate.

[beebe]

It turns out it won't matter. I'm going to copy the customers into the business, change their state, and then send their state back to the original customers. Thank you anyways.