Interview question: Objects eligible for garbage collection

Question

Give the following code:

class A {
    Boolean b;
    A easyMethod(A a){
        a = null;
        return a;
    }
    public static void main(String [] args         


        

Answer 1

For a2's original referant it actually completely depends on what happens in "some other code". If "some other code" doesn't use a2 or a3, then the original a2 object is eligible for garbage collection.

That's because the runtime doesn't have to care about lexical scope. It just needs to know that an object can never be referenced again. Therefore, if "some other code" doesn't utilize a2 or a3, the object they point to can never be referenced again and so is already available for garbage collection.