Garbage Collection question

[putti don]

Given the following,

public class X
{
public static void main(String args[])
{
X x=new X();
X x2=m1(x);
X x4=new X();
x2=x4;//6
}
static X m1(X mx)
{
mx=new X();
return mx;
}
}
 

After line 6 runs. How many objects are eligible for garbage collection?
0
1
2
3
4

Answer is 1.
can anyone explain what will happen to the object, referece variable mx is pointing to?
[ September 13, 2005: Message edited by: Michael Ernest ]

[Michael Ernest]

Which line is supposed to be line 6?

[putti don]

I have marked the line 6 with a comment. (//6)

[A Kumar]

Hi,


X x=new X(); //This object has a reference at the end of line 6

X x2=m1(x); //An object is returned from the method and x2 holds the
//reference

X x4=new X(); //This object has a reference at the end of line 6

x2=x4;//6 //x2 is relinquishing its reference to the original object
// and is pointing to the object stored in x4
//Remember that you are creating objects using new operator...

So at the end of line 6 you have one object (orginally created by the method execution ) that doesnt have any reference & ...so can be "GC"ed...

Regards

[putti don]

Hi,
are x2 and mx pointing to same object after the method m1() returns in line 4?
Thanks.

[manogna edintipal]

I believe that the variable mx will not be in scope after the method returns...sure enough within the method..it does point to the object..created..and after it returns....x2 points to the same object..

but within main....mx is not available..


Hope u got it...

[agrah upadhyay]

Hello Mr. Manogna Alias Sanju,
I'm Not Agree With U That x2 is pointing 2 same object
Instead Now x2 Is Pointing To x4.Just Stick To Pointer Diagram.


Agrah
3rd Year B.tech
Bioinformatics.

[A Kumar]

hi agrah,

What Manogna was referring to the line where the method call is happeneing...

that is before the statement x2=x4;

But after x2=x4...yes it does point to x4..

Regards