class X2
{
public X2 x;
public static void main(String [] args)
{
X2 x2 = new X2(); /* Line 6 */
X2 x3 = new X2(); /* Line 7 */
x2.x = x3;
x3.x = x2;
x2 = new X2();
x3 = x2; /* Line 11 */
doComplexStuff();
}
}
after line 11 runs, how many objects are eligible for garbage collection?
Answer: C
This is an example of the islands of isolated objects. By the time line 11 has run, the objects instantiated in lines 6 and 7 are referring to each other, but no live thread can reach either of them.