comparing a function execution in a loop and outside loop in C#.

No problem.
Run one inside of a separate thread then use some locking technique in the object to prevent dual access.

ps.  Your question doesn't really make sense, I suspect what I suggest isn't really what you want to do even though it is what you ask for.

Hi;

I want to find the changes of the objects that the function may cause a change inside and outside of the loop.

Regards.

OK, my first comment still does what you want.

ps.
Say your object has a int value.  Setting it to 42 will result in the object containing 42, it doesn't matter if you set that inside or outside of a loop.

My object has several objects in it which may get affected.

Can you provide a simple code for this locking inside and outside of the loop?

There are various possibilities to prevent simultaneous access to an object.  This is one method:

lock Statement (C# Reference), msdn reference site,

http://msdn.microsoft.com/en-us/library/c5kehkcz.aspx

but actually this is a comparison case. I mean I just need to test the behaviour of the same function inside and outside of the loop..