Existance of a Static variable.

[Duggi]

Hi

When does a static variable come into life? Well, as far as my
knowledge goes, I think it is during the execution of static
constructor. Because thats the logic point in the program where the
usage of static variable starts.

however from the following program sample, I see that static variables
will come into existence even before the static constructor gets
invoked.

public class A
{
public static B abc = new B("from decalration");

static A()
{
abc = new B("From Constructor");
}

}

public class B
{
public B(string message)
{
Console.WriteLi ne(message);
}
}

public class TestPrg
{
public static void Main()
{
A a = new A();

Console.ReadLin e();
}
}


Please let me know if I am wrong or your view on it.

-Cnu

[Jon Skeet [C# MVP]]

Re: Existance of a Static variable.

Duggi <DuggiSrinivasa Rao@gmail.comwr ote:

Thanks for pulling out the specification from ???

http://download.microsoft.com/download/3/8/8/388e7205-bc10-4226-b2a8-

75351c669b09/CSharp%20Langua ge%20Specificat ion.doc

If a static constructor (§10.12)

exists in the class, execution of the static field initializers occurs
immediately prior to executing that static constructor.

So a static variable will come into existance even before the static
constructor gets the control ?

Again, it's not a case of when the variable "comes into existence" -
it's when the initializer is executed. And yes, the initializer is
executed before the static constructor is executed.

--
Jon Skeet - <skeet@pobox.co m>
Web site: http://www.pobox.com/~skeet
Blog: http://www.msmvps.com/jon.skeet
C# in Depth: http://csharpindepth.com

[Duggi]

Re: Existance of a Static variable.

On Sep 22, 6:11 pm, Jon Skeet [C# MVP] <sk...@pobox.co mwrote:

Duggi <DuggiSrinivasa ...@gmail.comwr ote:

Thanks for pulling out the specification from ???

>

http://download.microsoft.com/download/3/8/8/388e7205-bc10-4226-b2a8-

75351c669b09/CSharp%20Langua ge%20Specificat ion.doc
>

If a static constructor (§10.12)

exists in the class, execution of the static field initializers occurs
immediately prior to executing that static constructor.

>

So a static variable will come into existance even before the static
constructor gets the control ?

>
Again, it's not a case of when the variable "comes into existence" -
it's when the initializer is executed. And yes, the initializer is
executed before the static constructor is executed.
>
--
Jon Skeet - <sk...@pobox.co m>
Web site:http://www.pobox.com/~skeet 
Blog:http://www.msmvps.com/jon.skeet
C# in Depth:http://csharpindepth.com

Thanks Jon.

Is there any difference between, "comes into existence" and execution
of initializer??

-Cnu

[Jon Skeet [C# MVP]]

Re: Existance of a Static variable.

Duggi <DuggiSrinivasa Rao@gmail.comwr ote:

Is there any difference between, "comes into existence" and execution
of initializer??

Yes. All the variables effectively "come into existence" at the same
time, before any of the initializers are executed. Consider the
following program:

public class Test
{
static int first = SumFirstAndSeco nd();
static int second = SumFirstAndSeco nd();

private static int SumFirstAndSeco nd()
{
return first + second;
}

static void Main(string[] args)
{
// No-op
}
}

The initializer for first calls SumFirstAndSeco nd, which uses both
first and second, so both variables must *exist* (and be addressable)
at that point. However, the initializer for first is still executing
and the initializer for second hasn't even begun executing at that
point.

--
Jon Skeet - <skeet@pobox.co m>
Web site: http://www.pobox.com/~skeet
Blog: http://www.msmvps.com/jon.skeet
C# in Depth: http://csharpindepth.com