Q from http://examsguide.com/ - GC eligible

[Clay Chow]

From http://examsguide.com/scjp/freequestions2.html:

For the below code, how many objects are eligible for collection after line 6 ?

Answer says 2.
But I can only see 1 object is eligible.
After line 3, c1 points to object1.
After line 4, object1 becomes eligible; both c1,c2 point to new object2.
After line 5, c3 points to object3.
After line 6, c2, c3 point to object3; c1 still points to object2.

class C
{
public static void main(String a[])
{
C c1=new C();       //3
C c2=m1(c1);         //4
C c3=new C();       //5
c2=c3;              //6
anothermethod();
}
static C m1(C ob1){
ob1 =new C();
return ob1;
}
}

after line 6, how many objects are eligible for garbage collection?


Ans: 1

Ans: 2

Ans: 3

Ans: 4

None of the above

Explanation:
No Explanation Available




Also another one from the same page: these may just be badly formated, but the below code seems to create only 2 objects.


14)

1. StringBuffer s1 = new StringBuffer("abc");
2. StringBuffer s2 = s1;
3. StringBuffer s3 = new StringBuffer("abc");
How many objects are created ?


0

Ans: 1

Ans: 2

Ans: 3

Explanation:
No Explanation Available

Ans: 4
[ November 26, 2008: Message edited by: Clay Chow ]

[Joanne Neal]

The first question has already been discussed numerous times (search these forums for 'anotherMethod').

The answer to the second question depends on the exact wording of the question - when that particular code is executed only two objects are created (the 2 StringBuffers). However, at the time the class was loaded, a String containing the value "abc" would also have been created.