Question

I can’t figure out an SCJP questions even after getting the right answer:

From the following code(source: http://scjptest.com), we need to determine when is object referenced as myInt be eligible for garbage collection:

01.public void doStuff() {  
02.    Integer arr[] = new Integer[5];  
03.    for (int i = 0; i < arr.length; i++) {  
04.        Integer myInt = new Integer(i);  
05.        arr[i] = myInt;  
06.    }  
07.    System.out.println("end");  
08.}

The answer states that it is eligible for GC on line 6. But I think the object is simply not eligable for GC until after line 7. Because, the object being referenced as myInt is also referred to as arr[i] as well. So, don’t you think, since, after myInt going out of scope, arr[] still has a reference to it till line 8?

Answer 1

arr[i] = myInt creates a copy of the reference to new Integer(i), not a reference to myInt; therefore, myInt isn’t strictly required to exist after that assignment.