garbage collection

[maggie karve]

public class NewGarb {
    2.    public static Object getIt() {
    3.      Object rg = new Integer(3);
    4.      Object dg[][] = new Object[1][2];
    5.      dg[0][1] = rg;
    6.      dg[0][0] = rg;
    7.      rg = null;
    8.      return rg;
    9.    }
    10.  }Which statement is true?

	(1)	The NewGarb class will not compile
	(2)	The getIt() method must not be declared as static
	(3)	The NewGarb class compiles, but an exception is received because dg is not set to null
	(4)	The rg object is eligible for garbage collection after a call to the getIt() method has returned
		

	Answer : 4
	Explanation : 
Option 4 is correct because no accessible references to the object created at line 3 exist after the method returns. This is because automatic variables are used for all the references in this code.Option 1 is incorrect because the NewGarb class compiles successfully. Option 2 is incorrect because the getIt() method may or may not be declared static. Option 3 is incorrect because an exception is not received.

according to k and B if an objct is returning a value from a method it is not eligible for garbage collection right???then why is rg getting eligible???

[Raju Champaklal]

what is happening after the method returns

[Minhaj Mehmood]

curve karve wrote:according to k and B if an objct is returning a value from a method it is not eligible for garbage collection right???

Yes True.

curve karve wrote:
then why is rg getting eligible???

because method is returning null object.

[Phungsuk Wangdu]

another view could be because all are automatic variables aka local variables so after method completes all local variables are flushed only objects creted remain but still the reference is nulled so it is eligible for gc

[Phungsuk Wangdu]

well i think object dg could also be eligible for GC wat you say Minhaj

[Raju Champaklal]

ya true...minhaj is right..i didnt see that

[Raju Champaklal]

you are returning rg here...rg is null here...the two variables of the array are local to the array..they will be destroyed after the ethod returns...no one refers to the object anymore..so the object is eligible for gc

[Minhaj Mehmood]

James Carter wrote:well i think object dg could also be eligible for GC wat you say Minhaj

i mean to say getIt() will return a null reference.

[Phungsuk Wangdu]

YES that is true but dg must also be eligible for gc i guess ? it could be right or wrong

[maggie karve]

ok..got it..its only if the value rg was not referring to null then it was not eligible for garbage collection???

[Raju Champaklal]

actually if the method was returning soemthing and something was taking that value only then it wont be eligible for gc

[Minhaj Mehmood]

James Carter wrote:YES that is true but dg must also be eligible for gc i guess ? it could be right or wrong

yes off course think about the method level variables.

[maggie karve]

hey dg wont be eligible ...i feel because it pointing to Integer(3)....why will it get eligible....or just because of second last line assignment???m getting confused???

[Neha Daga]

please dont use quote tags when you want to say or ask something.

all the method local objects are eligible for gc after the method is complete unless it returns these object references and they have some live references.

[maggie karve]

hey thanks neha

[Raju Champaklal]

only one girl is required to remove all the confusion between so many idiot men

[Neha Daga]

thanks Ankur
but none is idiot here..its just what clicks your mind and when.
you cleared scjp with 91%, how can you say that?