object oriented programming

[saltyyyyy]

I have problem in the pointer aggregation, if we aggregate an array in a class to another class, how should we initialise them using a constructor? and also I have a switch case, but when I insert the option, it run but does not break even I had included the word break.

class Item
{
	public:
		string code;
		string name;
		int quantity;
		double totPrice;
		double itemPrice;
		Date date;
		Time time;
		
	public:
		Item(string code="", int quantity=0)
		{
			this -> code = code;
			this -> quantity = quantity;
		}
		
		void setPrice(double price)
		{
			itemPrice = price;
		}
		
		double getPrice()
		{
			return itemPrice;
		}
		
		void read()
		{
			cout << "Item's code': ";
			getline(cin, code); 
			cout << "Quantity : ";
			cin >> quantity; 
			date.readDate(); 
			time.readTime(); 
		}		
		
		void getDateTime()
		{
			date.dispDate();
			cout << ", ";
			time.dispTime();
		}
		
		void displayDetails()
		{
			cout << left
				 << setw(25) << code 
				 << setw(7)  << name
				 << setw(25) << itemPrice
				 << setw(9) << quantity; 
		}
		
		int getQuantity()
		{
			return quantity;
		}
		
		void setQuantity(int quantity)
		{
			this->quantity = quantity;
		}
};

class Customer
{
	private:
		Status status;
		string name, phone, IC;
		Item *itemList[];
		int numItem;
		char paymentMethod;
		Payment payment;
		string payType;
	
	public:
		Customer(string name="", string phone="", string IC="")
		{
			this->name = name;
			this->phone = phone;
			this->IC = IC; 
			numItem = 0;
		}
		
		string getName()
		{
			return name;
		}
		
		string getPhone()
		{
			return phone;
		}
		
		string getIC()
		{
			return IC;
		}
		
		void setName(string name)
		{
			this->name = name;
		}
		
		void setPhone(string phone)
		{
			this->phone = phone;
		}
		
		void setIC(string IC)
		{
			this->IC = IC;
		}
		
		bool getStatus(Status s)
		{
			bool status;
			
			if ((s.getAge()<=12) || (s.getAge()>=65) || (s.getMask() == false) || (s.getTemp()>=37.5))
			{
				status = false;
			}
			else
			{
				status = true;
			}
			
			return status;
		}
		
		void addItem(Item *i)
		{
			itemList[numItem] = i; 
		}
		
		void displayTotal(Item data[])
		{
			cout << "CODE\tITEM NAME\t\tCOST(RM)\tQUATITY\t\tTOTAL(RM)\n";
			
			for(int i=0; i<15; i++)
			{
				cout << data[i].code << "\t" << data[i].name << "\t\t" << fixed << setprecision(2) << data[i].itemPrice
					 << "\t\t";
				cout << "\t\t" << data[i].quantity
				 	 << "\t\t" << fixed << setprecision(2) << data[i].totPrice << endl;;
			}
		}
		
		void displayInfoCust()
		{
			cout << left;
			cout << "Name	:" << name  << endl 
				 << "Phone	:" << phone << endl 
				 << "IC		:" << IC << endl;
		}
		
		void displayInfoItem()
		{
			double price, totalPrice = 0;

			if (numItem == 0)
				cout << "\nNo item!" << endl;
			else
			{
				cout << "\nNumber of Item: " << numItem << endl;

				cout << left;
				cout << setw(4)  << "No"
					 << setw(25) << "Code"
					 << setw(7)  << "Name"
					 << setw(25) << "Price(RM)"
					 << setw(9)  << "Quantity" << endl;

				for (int i = 0; i < numItem; i++) 
				{
					cout << (i+1) << ".  "; 
					itemList[i]->displayDetails();
					itemList[i]->getQuantity(); 
					totalPrice += itemList[i]->getPrice(); 
					cout << itemList[i]->getPrice() << endl; 
				}

				cout << "\nTotal price = RM" << totalPrice
					 << endl << endl;
			}
		}
		
		char getPaymentMethod()
		{
			return paymentMethod;
		}
		
		void displayPaymentMethod()
		{
			if(paymentMethod == 'A')
			{
				payType = "cash";
			}
			else if(paymentMethod == 'B')
			{
				payType = "credit card";
			}
			else
			{
				payType = "debit card";
			}
			cout << "You will use " << payType << " to pay your bill." << endl;
		}
};

int main()
{
	Customer custObj; //Customer object
	Customer custList[SIZE]; 
	Item data[15];
	Status S;
	Item *itemPtr; //Item pointer

for(int i=0; i<numItem; i++)
					{
						//array aggregation use constructor how to do?
						data[i].Item(choice3, quantity);
						itemPtr = &data[i];
					}
return 0;
}

[dutch]

You can't use a constructor at that point since the object has already been constructed. Objects in arrays are default constructed when the array is created. So if you use an array then you need to modify the value of the object; you can't "construct" it a second time.

Alternatively, you could use a vector instead of an array.

vector<Item> data;
...
data.emplace_back(choice3, quantity);

[kbw]

Your "array" isn't quote what you think. It's a "pointer to" a "pointer to Item". The first "pointer" is just that, but thru the convenience of pointer arithmetic, you can store and access and array with it. You haven't stored an array, so there's no array to access.

If you were to implement item correctly, your Customer implementation would lots of "non-Customer" things, like memory allocations/releases, linked list management of a "node" ...

In C++, those data structures exist in the Standard Template Library, and we can just use them, as dutch did above.

std::vector is a resizeable array, with optional bounds checking. You should just that.

[saltyyyyy]

thank you! I havent learnt vector yet, but it works!

[kbw]

but it works!

I doubt it. It doesn't crash because you forget to increment numItem in:

void addItem(Item *i)
{
	itemList[numItem] = i; 
}

But you don't initialize itemList. That code overwrites whatever itemList happens to be pointing to. You never allocate space for the Item.

So you probably what to fix that stuff.