Object Oriented Design

Implementing Associations

You use pointers in three circumstances.
- For a "1 : 0 or 1" relationship
- For object sharing
- For polymorphism, to refer to an object that may belong to a base class or a derived class.
Examples:
- Since multiple bank accounts could share the same owner, it makes sense to use a pointer.
```
class Bank Account
{
   ...
private:
   Person* owner;
};
```
- A vehicle has multiple tires, but a tire can only be part of a single vehicle.
```
class Vehicle
{
   ...
private:
   vector<Tire> tires;
};
```