Garbage Collection Problem

[Mohit G Gupta]

      

class CardBoard {
  Short story = 200;
  CardBoard go(CardBoard cb) {
    cb = null;
    return cb;
  }
  public static void main(String[] args) {
    CardBoard c1 = new CardBoard();
    CardBoard c2 = new CardBoard();
    CardBoard c3 = c1.go(c2);
    c1 = null;
    // do Stuff
} }  
    

When // doStuff is reached, how many objects are created within main() {specify them} and which one's are eligible for GC?

i think 4 objects would be created i.e.
-c1 and Short variable contained in it
-c2 and Short variable contained in it
----only c1 and it's instance variable Short would be eligible for GC
but i have one doubt would c3 be eligible for GC too ?

[Christophe Verré]

Please QuoteYourSources.

[Ankit Garg]

Also do you have any guesses of your own about how many objects are eligible for GC??

[dipayan chatterjee]

Hi Mohit

i agree with Ankit , first try out the problem yourself and post what you think the answer would be, we can then identify where you went wrong( if your answer is wrong) in this way you will learn more buddy. so post your answer and we are always there to help you out

[Mohit G Gupta]

answer posted

[Ankit Garg]

mohit your answer is right. 4 objects were created and 2 were eligible for GC. As far as c3 goes, it never pointed to any object, it was null. c2 will not be eligible as passing it to go method doesn't makes it null (read this for more info)...

[Mohit G Gupta]

IF I REPLACE THE LINE
Short story = 200;
WITH
Short story;

then ,would there be 4 object created or 2 objects as no value would be assigned to story instance variable ?

[Ankit Garg]

If you don't assign story any value, then it won't point to any object so only 2 objects will be created (as you said yourself)...