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K&B doubt

 
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class CardBoard {
Short story = 5;

CardBoard go(CardBoard cb) {
cb = null;
return cb;
}

public static void main(String[] args) {
CardBoard c1 = new CardBoard();
CardBoard c2 = new CardBoard();
CardBoard c3 = c1.go(c2);
c1 = null;
// do something
}
}

Why at //do something c2 and c3 are not avaiable to gc??
 
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Hi Bruno,

setting the cb reference variable in the go method doesn't change the value of c2. So c2 has still the reference to the object.

c3 had never had a value other than null. No object, nothing to do for the garbage collector.
 
Bruno Abreuu
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Thank's...
 
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Originally posted by Manfred Klug:

setting the cb reference variable in the go method doesn't change the value of c2. So c2 has still the reference to the object.



But why c2 doesn't change?It was passed into go(c2),and c2=null?

In my opinion ,c2 point to null.
 
Manfred Klug
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Hi Zhao,

cb is a copy of the c2 object reference. Any changes to the object reference in the go method only changes the copy.
 
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Zhao zhenhua


In my opinion ,c2 point to null.



Saying this is technically incorrect! c2 is null, it does not point to null.
 
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