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6. christmas = new GregorianCalendar(2009,12,25);
7. newyears = new GregorianCalendar(2010,1,1);
8.
9. christmas = newyears;
10. GregorianCalendar d = christmas;
11. christmas = null;
12. }
13. }
The two
GregorianCalendar
objects are created on lines 6 and 7, resulting in the
references and objects that Figure 1.8 shows.
FIGURE 1.8
Each
GregorianCalendar
object has a reference pointing to it.
christmas
day
25
month
12
year
2009
newyears
day
1
month
1
year
2010
On line 9, the
christmas
reference is assigned to
newyears
, which results in no more
references pointing to the object from line 6, so this object immediately becomes available
for garbage collection after line 9. There is now only one
GregorianCalendar
object (from
line 7) reachable in memory, and after line 10 there are three references pointing to it, as
Figure 1.9 shows.
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