length of data type

[donald]

how to get the length of variable for differernt data type, such as data
type of structure, integer, date, etc.

Thanks in advance.

[Nicholas Paldino [.NET/C# MVP]]

donald,

You can't really get these from the system. Some people use the sizeof
operator (or Marshal.SizeOf method), but you can't do that, since it will
give you the size of the marshaled type (to unmanaged code).

For primitive types (things like int, bool, double, etc, etc), these
sizes are well known, but for classes and the like, the only way you can
determine that is through a hook into the CLR.

What exactly are you trying to do?
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"donald" <do*********@gmail.comwrote in message
news:eA**************@TK2MSFTNGP05.phx.gbl...

how to get the length of variable for differernt data type, such as data
type of structure, integer, date, etc.

Thanks in advance.

[Greg Young]

For all value types you can use sizeof()

The one issue with this is if the value type happens to be a structure and
happens to contain a reference type only the reference to the reference type
will be counted (not the size of the reference type as well).

Cheers,

Greg Young
MVP - C#
http://codebetter.com/blogs/gregyoung

"donald" <do*********@gmail.comwrote in message
news:eA**************@TK2MSFTNGP05.phx.gbl...

how to get the length of variable for differernt data type, such as data
type of structure, integer, date, etc.

Thanks in advance.

[Mattias Sjögren]

Greg,

>For all value types you can use sizeof()

The one issue with this is if the value type happens to be a structure and
happens to contain a reference type only the reference to the reference type
will be counted (not the size of the reference type as well).

If the struct contains a reference type field, you won't be able to
use sizeof on it at all (try it and you'll get a CS0208), so that's
not an issue.
Mattias

--
Mattias Sjögren [C# MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

[Greg Young]

You are right mattias .. I wasn't very clear in this case.

You can still use Marshall.SizeOf in such situations which is what I was
referring to ..

as an example ...

using System;
using System.Collections.Generic;
using System.Text;
namespace FreakShow {
struct foo {
string bar;
int foo1;
int foo2;
}
class Program {
static void Main(string[] args) {
foo f = new foo(
Console.WriteLine(System.Runtime.InteropServices.M arshal.SizeOf(f));
}
}
}

Will include the reference size to bar but not the actual size of bar when
determining the size.

Cheers,

Greg Young
MVP- C#
http://codebetter.com/blogs/gregyoung
"Mattias Sjögren" <ma********************@mvps.orgwrote in message
news:Oi**************@TK2MSFTNGP03.phx.gbl...

Greg,

>>For all value types you can use sizeof()

The one issue with this is if the value type happens to be a structure and
happens to contain a reference type only the reference to the reference
type
will be counted (not the size of the reference type as well).

If the struct contains a reference type field, you won't be able to
use sizeof on it at all (try it and you'll get a CS0208), so that's
not an issue.
Mattias

--
Mattias Sjögren [C# MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.