Question

I am currently working on atomic classes and I am unable to track whether it is “call by value” or “call by reference”. I understand that Java does not allow call by reference and that it is only and only call by value. But in case of atomic classes, it seems to be call by reference. Can you share your thoughts with me?

Answer 1

It’s called pass by value/reference, and it concerns passing arguments to methods.

Atomic classes are no exception to the pass-by-value:

public void method1() {
    AtomicInteger atomic = new AtomicInteger(5);
    method2(atomic);
    System.out.println(atomic.get()); // prints 5
}

public void method2(AtomicInteger atomic) {
   atomic = new AtomicInteger(7); // reassign, but this does not affect metod1
}