java garbage collection and null reference

Question

In my studying for OCJP I came across the following question:

class CardBoard {
           Short story = 200;
           CardBoard go(CardBoard cb) {
                


        

Answer 1

The c3 itself is just a reference variable, which is not in the heap space (i.e. not in the scope of garbage collection)

The line CardBoard c3 = c1.go(c2); only sets the c3 reference to null Thus c3 has not impact on garbage collection as it doesn't make any object eligible.