eligible objects

[ohimai anthony]

void start() {  
    A a = new A(); 
    B b = new B(); 
    a.s(b);  
    b = null; /* Line 5 */
    a = null;  /* Line 6 */
    System.out.println("start completed"); /* Line 7 */
} 

When is the B object, created in line 3, eligible for garbage collection?

[Edit - added code tags - see UseCodeTags for details]

[Matthew Brown]

Hi Ohimai. Welcome to the Ranch!

There's not actually enough information there to tell - it looks like part of the question is missing. It depends what the s() method of A does. If it doesn't save a reference to b then the B object is eligible for garbage collection after line 5. If it saves a copy of the reference in a then it will be eligible after line 6. But it would be entirely possible for it to do something (like saving a copy in a static reference) that would mean the B object is still not eligible at the end of this code.

[ohimai anthony]

i think because there are two aliases, refferring to the same object, the two ferences have to be nulled or out of scope for the object to be garbage collected.

[Matthew Brown]

So which two variables are pointing at the same object?