Object for GC....

[Ganeshkumar cheekati]

source:www.javabeat.net

class Harpic{
public void finalize(){
System.out.println("Harpic");
}
}
public class ArmitageShanks{
Harpic har;
public static void main(String argv[]){
ArmitageShanks as = new ArmitageShanks();
as.oui();
}
public void oui(){
har = new Harpic();
mno(har);
//one
har=null;
}
public void mno(Harpic har){
Harpic pic=har;
//two
pic=null;
//three
har=null;
}
}

At which point will the word "Harpic" be printed out when this code is executied?

(1) After executing the line after the comment //one
(2) After executing the line after the comment //two
(3) After executing the line after the comment //three
(4) It is impossible to say, the String "Harpic" may not be output at all

my answer is 1

but answer is 4

can anyone elaborate this?

[ December 16, 2008: Message edited by: Ganeshkumar cheekati ]

[James Tharakan]

One object is elligible for GC.
That is after the LINE1 ( As you thought.)
But the statement system.gc(); is not explictly written.
So GC may or may not happen.
Look at the option 4.
It is impossible to say, the String "Harpic" may not be output at all
[ December 16, 2008: Message edited by: James Tharakan ]

[Punit Singh]

See Harpic is printed in finalize() method. And JVM says it will run finalize atmost one. Here atmost means zero or one time. It is possible that the finalize method will never be called.

[Preethi Dev]

Hi Ganeshkumar,

here is my view..

public void oui()
{
har = new Harpic();
mno(har);//here we are passing the copy of har-one
har=null;//finally original har is made null- four.
}
public void mno(Harpic har)
{
Harpic pic=har;//here assingning the copr of har to pic
pic=null;//making pic null so -two
har=null;//here making the har null(which is the copy of har in oui())-three
}}

if "harpic" has to be printed out then the oringinal har would be consider as eligible for GC and run once, but it's not gaurenteed.

Preetha
[ December 16, 2008: Message edited by: Preetha Arun ]