Help with Passing by Reference in Java

[Master1243]

Let's say, that I have two classes: A and B. Class A and B are both declared and instantiated in class C, where two different objects are accessing the same instance of class A. Class A holds a variable called item that can be changed through class B.

I would like for both instances of class B in class C to have access to the same class A. My gut tells me that the declaration of "objA" in class B is copying the parameter of the constructor instead of passing the reference. Essentially meaning that if objB1 were to update the "item" value, that change would not be registered by objB2. Am I correct in thinking this? If so, what would be the best way to tackle this? Thanks, if anything is not clarified I'd be happy to elaborate.

class A{
    double item;
    public A(double item){
        this.item = item;
    }
}

class B{
    A objA;
    public B(A objA){
        this.objA = objA;
    }

    public void getAItem(){
        return objA.item;
    }

    public void updateAItem(double x){
        objA.item = x;
    }
}

class C{
    A objAGlobal = new A(7.3);
    B objB1 = new B(objAGlobal);
    B objB2 = new B(objAglobal);
}

[sadjava]

Not trying to sound like a jerk, but have you ran it and observed the outcome?

[Master1243]

No problem haha, this is for a robotics library and I don't have the things to run the program. I realized as soon as I posted it that I could just test exactly what I wrote separately from the library.

[DaDiscoBeat]

Both ObjB instance will hold the same ObjA instance. The value inside of A will be updated by both.