Question

Ho can I implement a Car class in the sample below. I can pass a collection with wheel to brand mapping but is there a better way of doing it?

A Car has an engine and some number of wheels. Not all cars are built to hold four wheels, some have only three while others have more. But whatever they are built for, that is the max number they can hold.When a car is built (i.e. constructed), an engine is created for it and so are the wheels that it will use.

Answer 1

public class Car
{
    private Engine      e;
    private int         numWheels;
    private List<Wheel> wheels;

    public Car(Engine e, int numWheels, ...)
    {
       this.e         = e;
       this.numWheels = numWheels;
       this.wheels    = new ArrayList<>();

       for(int i = 0; i < this.numWheels; i++)
       {
           this.wheels.add(new Wheel(...));
       }
    }
}

Just add an integer that holds the number of wheels THIS Car object can have. Then loop through in the constructor and add those wheels