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Serializable question

 
Chandra Bhatt
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10. class Car implements Serializable {
11. Wheels w;
12. }
13.
14. class Wheels { }

If you attempt to serialize an instance of Car, what is the result?

A. Compilation fails.
B. One object is serialized.
C. Two objects are serialized.
D. An exception is thrown at runtime.


What will be the correct answer?


Source: Sun practice exam


[EDIT] YEAH Swarna, I say that too, but the source says 'B'.
Surprised!!!

Thanks,
cmbhatt
[ April 27, 2007: Message edited by: Chandra Bhatt ]
 
swarna dasa
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how abt D?
 
megha joshi
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Ya they say that
I understand it as follows:

Wheels is a object which cannot be serialized. Cars can be serialized. Wheels is not instantiated yet inside Cars so Cars object does not have Wheels object. Thus Cars object can be serialized and one object gets serialized. If Wheels object would have been instantiated then the Cars object would have a wheels object inside it and in that case that object cannot be serialized. It would throw NotSerializable exception then.

Its not easy to be a compiler
[ April 27, 2007: Message edited by: megha joshi ]
 
swarna dasa
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should have guessed it, if it was as simple as D, you wouldn't have posted it in the first place
 
Chandra Bhatt
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Yeah, You took the question in right way!

Until, Wheels is instantiated, no problem to serialize the Cars object,
which HAS-A Wheels.



Its not easy to be a compiler.


But I am sure It not easy to think like a programmer, for the compiler.



Thanks,
cmbhatt
 
Barry Gaunt
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Just one small point. I take it that this question is not one of those from Sun's Practive Exam that you have agreed to not to disclose? That is, it is not from Sun's online US$ 75 test?
[ April 28, 2007: Message edited by: Barry Gaunt ]
 
Abdul Mohsin
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10. class Car implements Serializable {
11. Wheels w;
12. }
13.
14. class Wheels { }


just check the answer when we create new Wheels

Wheels w= new Wheels();


Thanks,

Abdul Mohsin
 
Rahul Bhattacharjee
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Originally posted by swarna dasa:
how abt D?


I too go with D.
 
Chandra Bhatt
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Hi all,


class Car implements Serializable {
Wheels w;
}

class Wheels { }



I do agree with you all, but only when a new instance of the Wheels is created. In this question option "B" is correct. Having only a reference of
the class that is not Serializable is no more sin that could hinder the proper Serialization of the containing class object.

Megha described the rest part very well.

Barry, the question I picked from says "Courtesy to sun practice exam"!
What to do, should I remove this question?
[ April 30, 2007: Message edited by: Chandra Bhatt ]
 
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