How to Float an Object in an Application

Question

Dear Friends ,
I am woking in an application ,
In My application , I want to pass a String in CLASS A to the constructer of another object of CLASS B.
The String will dynamically change eveny after the another object of CLASS B is created .
How do I reflect the changes made in this String also in the other object ( to which the string was passed in its constructer ) .
For ex -
In CLASS A
String s ;
method()
s = "ADD";
"Object created when s = "ADD" "
new CLASSB(s);
method2()
s = "SUB";
In CLASS B
"constructer"
CLASSB( String s )
So if the CLASS A's Object Calls the Constructer of CLASS B with s= "ADD";
Now it changes to s = "SUB"
Now how do i reflect the change in Object of CLASS B .
Some one said it can be done by Hashcode .
I wont know how to implement it ,
Suggestions in this regard

Answer 1

I [iwould[/i] like to know
why It doesn't work for variables other than Array
I used String instead of String[ ] but it doesn't
work .
Please let me know the Reason .Strings are immutable.
Java passes arguments by value (with primitives this
is a reasonably intuitive thing).
All non-primitives variables are references.
You can assign  String myString =
"foo";and later you can change it to reference
a different immutable String  myString =
"bar";When you pass myString to a method you
are passing a reference to the immutable String it is
referencing.Everything in java is passed by value. Nothing is passed by references. So in case of objects, the objects are never passed but the references are passed by value. A subtle but important difference.
The method has no access to your myString reference
variable.
If you pass a reference to  String[]
myStringArray = { "foo" };to a method, the same
goes; the method has no access to your myStringArray
reference variable, but
it does have its own copy of the reference so
it can access the array and it can change the elements
in the array.Except for that minor thing that I mentioned tschodt has mentioned all the rest perfectly.
cheers