design question : struct or class

[phoenix]

Hello,

I've got a design question. I need to keep track of some variables and I am
planning to put them inside a class or struct. Basically I'm talking about
10 bools, 20 ints and 2 arrays of ints. The size of the arrays would depend
on some external value (going from 0 to around 1000 max). I would have an
array of max 255 of these classes/structs (in most cases it will be less
then 5 however)

Since there's no real business logic my choice would be structs. But looking
at the size of the objects in memory I would think they are a bit large to
put on the stack and should be better of on the heap. Which would mean I
should use classes.

Any ideas about what would be best?

TIA

Yves

[L#]

On Sun, 1 Feb 2004 11:26:10 -0700, "Joe Mayo [C# MVP]"
<jm***@nospamAt CSharpDashStati on.com> wrote:

application. I've never seen or heard anything that would make me believe
that the size of a value type determines whether they reside on the stack or
on the heap.

Mmm, indeed, I thought I read somewhere that the framework checks
this, but apparently it doesn't, because using large structs has a
negative effect in perfomance.

[Source:
http://msdn.microsoft.com/library/de...assStruct.asp]

We learn, every day.

--
Ludwig
mailto:ludwig_( nospamplease)st uyck@pandora(no spamplease).be

[peter x]

Enjoyed the article - thanks for pointing it out :) Peter
"L#" <ludwig_(nospam please)stuyck@p andora(nospampl ease).be> wrote in message
news:0f******** *************** *********@4ax.c om...

On Sun, 1 Feb 2004 11:26:10 -0700, "Joe Mayo [C# MVP]"
<jm***@nospamAt CSharpDashStati on.com> wrote:

application. I've never seen or heard anything that would make me believethat the size of a value type determines whether they reside on the stack oron the heap.
Mmm, indeed, I thought I read somewhere that the framework checks
this, but apparently it doesn't, because using large structs has a
negative effect in perfomance.

[Source:

http://msdn.microsoft.com/library/de...assStruct.asp]
We learn, every day.

--
Ludwig
mailto:ludwig_( nospamplease)st uyck@pandora(no spamplease).be

[Jon Skeet [C# MVP]]

<L# <ludwig_(nospam please)stuyck@p andora(nospampl ease).be>> wrote:

No they are not. "Pass by reference" has a very specific meaning, and
it *doesn't* apply here (unless you use the ref modifier). There is a
big difference between a reference being passed by value (which is what
actually happens) and a parameter itself being passed *by* reference.

See http://www.pobox.com/~skeet/csharp/parameters.html for more
information.
Being objects, they are passed by value; meaning that the pointer to
the object is passed by value.

Passing an object doesn't happen in .NET. Only passing a reference
happens - and as you say, it's passed by value by default in C#.
Eventually it has the same effect as
being passed by reference.
No it doesn't.
Placing the ref keyword in front of it, won't make a difference.

Yes it will. Here's a sample program:

using System;

public class Test
{
static void Main()
{
string x = "hello";
PassByValue (x);
Console.WriteLi ne (x);
PassByRef (ref x);
Console.WriteLi ne (x);
}

static void PassByValue (string y)
{
y = "there";
}

static void PassByRef (ref string y)
{
y = "there";
}
}

PassByValue and PassByRef are identical apart from the way in which
their parameters are passed - yet they have completely different
effects.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

[L#]

On Mon, 2 Feb 2004 08:06:35 -0000, Jon Skeet [C# MVP]
<sk***@pobox.co m> wrote:

Placing the ref keyword in front of it, won't make a difference.

Yes it will. Here's a sample program:

But doesn't String behave completely different than other Objects?
--
Ludwig
mailto:ludwig_( nospamplease)st uyck@pandora(no spamplease).be

[Jon Skeet [C# MVP]]

<L# <ludwig_(nospam please)stuyck@p andora(nospampl ease).be>> wrote:

Placing the ref keyword in front of it, won't make a difference.

Yes it will. Here's a sample program:

But doesn't String behave completely different than other Objects?

No. What makes you say it does?

If you want an example which doesn't use strings at all, here it is:

using System;

public class Test
{
int number;

public int Number
{
get { return number; }
}

Test (int number)
{
this.number = number;
}

static void Main()
{
Test t = new Test(10);
PassByValue(t);
Console.WriteLi ne (t.Number);
PassByRef(ref t);
Console.WriteLi ne (t.Number);
}

static void PassByValue (Test t)
{
t = new Test(20);
}

static void PassByRef (ref Test t)
{
t = new Test(20);
}
}

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

[L#]

On Mon, 2 Feb 2004 11:21:25 -0000, Jon Skeet [C# MVP]
<sk***@pobox.co m> wrote:

No. What makes you say it does?

If you want an example which doesn't use strings at all, here it is:

So if you modify the object, there's no difference in passing by
value/passing by reference; but if you create a new object, there's a
difference. Didn't know that!
--
Ludwig
mailto:ludwig_( nospamplease)st uyck@pandora(no spamplease).be

[Jon Skeet [C# MVP]]

<L# <ludwig_(nospam please)stuyck@p andora(nospampl ease).be>> wrote:

So if you modify the object, there's no difference in passing by
value/passing by reference; but if you create a new object, there's a
difference. Didn't know that!

The important difference is that modifying the object a parameter's
value refers to doesn't actually change the value of the parameter.
Changing the value of the parameter (e.g. by creating a new object, but
that's only one type of new value) is the important thing, and that's
where the difference between pass-by-reference and pass-by-value
semantics lies.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too