When destroy an object?

Question

1.00/5 (2 votes)

See more:

Here is the question.

Which of the following statements about garbage collection is false?

a. In general, you can’t tell when the GC will perform garbage collection.
b. It is possible for a program to run without ever performing garbage collection.
c. An object’s Dispose method can call GC.SuppressFinalize to prevent the GC from calling the object’s destructor.
d. Before destroying an object, the GC calls its Dispose method.
I think that the answer is d but not sure. Would you explain it?

Posted 16-Feb-15 5:40am

zhshqzyc

Add a Solution

Comments

E.F. Nijboer 16-Feb-15 11:44am

Looks like homework. This is something you can (or should be able to) figure out yourself. Good luck!

[no name] 16-Feb-15 11:48am

It is not home work. I am self practicing C#. The question can be obtained online at https://books.google.com/books?id=WvrR3piDrbkC&pg=PA201&lpg=PA201&dq=Before+destroying+an+object,+the+GC+calls+its+Dispose+method&source=bl&ots=dYgqBRiMu6&sig=jUYIZCjTM8g100KQ97iQUnYCIDE&hl=en&sa=X&ei=NB_iVJ_9JYfAggT4y4G4Bw&ved=0CEQQ6AEwBg#v=onepage&q=Before%20destroying%20an%20object%2C%20the%20GC%20calls%20its%20Dispose%20method&f=false

E.F. Nijboer 16-Feb-15 12:13pm

Ah okay, but then the information should be available in the book itself.
But to help you out, I also think the answer is D because this only is true if you actually implement IDisposable.

Zoltán Zörgő 16-Feb-15 11:46am

"d" is easy to test, as you can force GC to collect. If if write something to the output in the dispose method, you will see if it is called or not.
This could be useful: https://msdn.microsoft.com/en-us/library/system.object.finalize.aspx

PIEBALDconsult 16-Feb-15 11:56am

The whole point of Garbage Collection is that the developer doesn't need to know anything about what it does when, just trust that it will do its thing. So even if you know the correct answer, it just doesn't matter in the real world.

[no name] 16-Feb-15 12:01pm

Do you mean it can be either before destroying an object or after it?

PIEBALDconsult 16-Feb-15 12:04pm

I mean you don't need to know.

Sergey Alexandrovich Kryukov 16-Feb-15 13:00pm

Please have enough respect not to offer multiple-choice test questions here. I do understand that your school does not have enough respect to you if they test you this way, but you are asking experts, so don't do such things. Ask a question you have, not the question your school offers to you.
—SA

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Accepted Answer · 2015-02-16T06:42:00

Well, think about it:
a) Can you tell when the GC is running? If so, how?
The whole idea of a GC is that you can't tell, unless you force the GC to run.
b) Can a program run without the GC running at all? Can you write a program that would never need the GC?
Of course you can! If your Main method creates no objects, and exits immediately, then the GC is never needed because memory never becomes low.
c) Look at the documentation: MSDN[^]
It includes the line: "The Dispose method performs all object cleanup, so the garbage collector no longer needs to call the objects' Object.Finalize override. Therefore, the call to the SuppressFinalize method prevents the garbage collector from running the finalizer."
So yes, you can call SuppressFinalize and it will suppress the destructor call, because the clean-up is already done and does not need to be repeated.

So that leaves D as false.
And the Answer to C covers why.