Object Searching...

Question

I need to be able to have one Object(Object A) use another object (Object B) somewhere in my program. However, there is no information about Object B stored anywhere within Object A. The only definite thing is that there is an Object A and an Object B in my program. There is only one Object B, but it could be in any of my programs objects.
I'll place some code to make it simpler
class program {
    public static void main(){
        Object_A OBA = new Object_A();
        Object_B OBB = new Object_B();
        OBA.alter();
class Object_A {
    //changes object B's value
    private int ObjectBsValue;
    public Object_B() {}
    public void alter(int num) {
        //Here is where my problem is:  Object B could appear anywhere
        //in my program, so I can't rely on it being anywhere
        [wherever OBB is].myValue++;
        ObjectBsValue=[wherever OBB is].myValue;
class Object_B {
    public int myValue;
    public Object_B() {}
}I'm guessing there is a way to search for objects, but I don't know where to look for information.
I'd like a solution to my problem, or an explanation why it can't be done. If not that, then a pointer in the right direction.

Answer 1

Sorry, I was a little inaccurate when I was describing the problem. When I was looking at the documentation you referred to, i realized that I could take advantage of my program's heierarchy to find the object in question. I'm pretty sure I would have figured out how wo use observers and watchers if the solution my problem hadn't become apparent while reading...
I'll award you the Duke Dollars because my problem was solved while I was reading something you talked about.