Trouble using aggregate classes

Hey everyone, I'm pretty new with Java and am preparing for a class I'm taking later this summer. I've been doing a lot of self study and have been attempting to get as far as I can in some Java books by myself. Right now I'm working on a carpet calculator problem and I'm a bit stuck. I'm attempting to create a RoomDimension class to set the area of a room, then use a method from that class to establish an argument in a RoomCarpet class which calculates the total cost of of carpeting for the room.

Code Java:

---

public class RoomCarpet {
 
    private double carpetCost;
    private double roomSize;
    private RoomDimension yourSize;
 
    // This is what I'm having trouble with 
 
    public RoomCarpet(double cost, double roomsize){ // I'm not sure if I should use double or a RoomDimension object as the parameter
 
        carpetCost = cost;
        yourSize = new RoomDimension(); // I'm not sure what to pass as arguments here
        roomSize = yourSize.getArea();
 
    }
...

---

and here's the RoomDimension class:

Code Java:

---

public class RoomDimension {
 
    private double length;
    private double width;
 
    public RoomDimension(double len, double w){
 
        length = len;
        width = w;
 
    }
 
    public RoomDimension(RoomDimension object2){
 
        length = object2.length;
        width = object2.width;
 
    }
 
    public double getArea(){
 
        return length * width;
 
    }
 
    public String toString(){
 
        String str;
 
        str = "This rooms area is " + getArea();
 
        return str;
    }
 
}

---

I'd appreciate any help I can get. Thanks!

You could always have both.

Create a second one that will initialize your current object to the values of the parameter object.

Use getters and setters, like setLength(), setWidth(), setCost(), etc. You do need a RoomDimension constructor with 0 arguments in order to do that. By default it makes one if there none but doesn't if there are any others.

Code java:

---

public RoomCarpet(double cost, double roomsize){ // I'm not sure if I should use double or a RoomDimension object as the parameter
 
        carpetCost = cost;
        yourSize = new RoomDimension(); // I'm not sure what to pass as arguments here
        roomSize = yourSize.getArea(); // Why are you doing that?  You're changing the parameter's value?  
 
    }
 
public void setCost(double cost)
{
carpetCost = cost;
}
 
public double getCost()
{
return carpetCost;
}
 
public void setRoomSize(double roomSize)
{
this.roomSize = roomSize;  // this refers to the RoomCarpet object itself
 
}
 
public double getRoomSize()
{
return roomSize;
}
 
public RoomCarpet(RoomCarpet rc)
{
setCost(rc.getCost());
setRoomSize(rc.getRoomSize());
 
 
}

---

this is inheritance or not ?

No it's not inheritance. If anything, it's composition (or aggregation) hence the thread title.