ooad

I'm going to try to ask my question in the context of a simple example... Let's say I have an abstract base class Car. Car has-a basic Engine object. I have a method StartEngine() in the abstract Car class that delegates the starting of the engine to the Engine object. How do I allow subclasses of Car (like Ferrari) to declare the Engine object as a specific type of engine (e.g., TurboEngine)? Do I need another Car class (TurboCar)? I'm inheriting a plain old Engine object and I cannot re-declare (or override) it as a TurboEngine in my Car subclasses. EDIT: I understand that I can plug any

I have read in many places that "getters and setters are evil". And I understood why so. But I don't know how to avoid them completely. Say Item is a class that has information about item name, qty, price etc... and ItemList is a class, which has a list of Items. To find the grand total: int grandTotal() { int total = 0; for (Item item: itemList) total += item.getPrice(); return total; } In the above case, how does one avoid getPrice()? The Item class provides getName, setName, etc.... How do I avoid them? Jonathan Fingland When should you use getters and setters? Getters and setters are great

I'm beginning to study OOAD and I'm having difficulty finding a C++ code example that'd illustrate how Association , Aggregation and Composition are implemented programmatically. (There are several posts everywhere but they relate to C# or java). I did find an example or two, but they all conflict with my instructor's instructions and I'm confused. My understanding is that in: Association: Foo has a pointer to Bar object as a data member Aggregation: Foo has a pointer to Bar object and data of Bar is deep copied in that pointer. Composition: Foo has a Bar object as data member. And this is how

I am on the quest to be a good OO-developer. OO intrigues me, because I understand the patterns, know why composition gives you more flexibility then inheritance, and more of such wisdom. However, I came to the conclusion that I know how to implement a factory of a singleton, but that I do not know how to come up with a robust OO design . I have a bunch of books Design Patterns by the GoF AntiPatterns Brown et al. Refactoring by Fowler Code complete 2 They might be very good books, but they don't teach you to architect an application. I am often paralysed by some very basic decisions ( example

I have two tables: tblCustomer , tblProduct : tblCustomer: Id: Integer, auto-increament Name: Varchar(30) .... tblProduct Id: Integer, auto-increament Name: Varchar(50) customerId: Integer .... And two classes: Customer , Product : public class Product { private int id; private int name; /* Other stuffs */ } public class Customer { private int id; private String name; private String phoneNumber; /* get-set and others stuffs */ public static boolean add(Customer cus) { /* This is for insert a customer to tblCustomer */ } public boolean addProduct(Product pd) { /* This is for insert a product to