Problem with objects and automatic numbering in VB.NET

[johndevlon]

Hi everyone,

I'm having a small problem using objects in VB.NET.

I've created a class "Shop" and one of its properties is a number which
I've named "intNumber" (Integer).

I've created several objects of the class Shop and everythink works
fine. What I'm trying to do is to modify my class in such a manner that
when a create a new object, the property "intNumber" has already a
value. Using a constructor you can do this but I would like to give
each object a different number, starting at 1 or 0, increasing 1 each
time a new object has been created...

The first object has automatically number 1 assigned to "intNumber" ,
the second number 2, etc...

I know this is possible but have forgotten how to do this ...

Many thanks

John

[Patrik Löwendahl [C# MVP]]

Hello john

Use a static variable to hold the last number:
public class Shop {
private static int nextNumber = 0;
private int number;

public int Number {
get { retun this.number; }
}

public Shop() {
this.number = nextNumber;
nextNumber++;
}

}
--
Patrik Löwendahl [C# MVP]
http://www.lowendahl.net
http://www.cornerstone.se

Hi everyone,

I'm having a small problem using objects in VB.NET.

I've created a class "Shop" and one of its properties is a number
which I've named "intNumber" (Integer).

I've created several objects of the class Shop and everythink works
fine. What I'm trying to do is to modify my class in such a manner
that when a create a new object, the property "intNumber" has already
a value. Using a constructor you can do this but I would like to give
each object a different number, starting at 1 or 0, increasing 1 each
time a new object has been created...

The first object has automatically number 1 assigned to "intNumber" ,
the second number 2, etc...

I know this is possible but have forgotten how to do this ...

Many thanks

John

[Jon Skeet [C# MVP]]

<jo********@hotmail.com> wrote:

I'm having a small problem using objects in VB.NET.

I've created a class "Shop" and one of its properties is a number which
I've named "intNumber" (Integer).

I've created several objects of the class Shop and everythink works
fine. What I'm trying to do is to modify my class in such a manner that
when a create a new object, the property "intNumber" has already a
value. Using a constructor you can do this but I would like to give
each object a different number, starting at 1 or 0, increasing 1 each
time a new object has been created...

The first object has automatically number 1 assigned to "intNumber" ,
the second number 2, etc...

I know this is possible but have forgotten how to do this ...

Use a Shared variable to keep track of how many instances have been
created before. Don't forget threading - either acquire a lock while
you're incrementing, or use the Interlocked class.

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

[Patrik Löwendahl [C# MVP]]

Hello Patrik,

LOL sorry, read johns post. Shared is the correct term in VB.NET. A bit to
quick there.
--
Patrik Löwendahl [C# MVP]
http://www.lowendahl.net
http://www.cornerstone.se

Hello john

Use a static variable to hold the last number:

public class Shop {
private static int nextNumber = 0;
private int number;
public int Number {
get { retun this.number; }
}
public Shop() {
this.number = nextNumber;
nextNumber++;
}
}

--
Patrik Löwendahl [C# MVP]
http://www.lowendahl.net
http://www.cornerstone.se

Hi everyone,

I'm having a small problem using objects in VB.NET.

I've created a class "Shop" and one of its properties is a number
which I've named "intNumber" (Integer).

I've created several objects of the class Shop and everythink works
fine. What I'm trying to do is to modify my class in such a manner
that when a create a new object, the property "intNumber" has already
a value. Using a constructor you can do this but I would like to give
each object a different number, starting at 1 or 0, increasing 1 each
time a new object has been created...

The first object has automatically number 1 assigned to "intNumber" ,
the second number 2, etc...

I know this is possible but have forgotten how to do this ...

Many thanks

John

[johndevlon]

Hi,
Many thanx for the fast responses.

Jon, could you please give a small example ?

John

[Jon Skeet [C# MVP]]

<jo********@hotmail.com> wrote:

Jon, could you please give a small example ?

Something like this:

Imports System
Imports System.Threading

Class Test

Shared instancesCreated As Integer

Dim id As Integer
Sub New
id = Interlocked.Increment (instancesCreated)
End Sub
Shared Sub Main()

Dim x0 As New Test
Dim x1 As New Test
Dim x2 As New Test
Dim x3 As New Test

Console.WriteLine (x0.id)
Console.WriteLine (x1.id)
Console.WriteLine (x2.id)
Console.WriteLine (x3.id)

End Sub
End Class

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

[TalkUdaiAboutBiz]

Hi John,

You must define it as a static member and try working around this.

Regards

Udai.M
Team Leader,Consultant
Chimeratechnologies
Bangalore
"jo********@hotmail.com" wrote:

Hi everyone,

I'm having a small problem using objects in VB.NET.

I've created a class "Shop" and one of its properties is a number which
I've named "intNumber" (Integer).

I've created several objects of the class Shop and everythink works
fine. What I'm trying to do is to modify my class in such a manner that
when a create a new object, the property "intNumber" has already a
value. Using a constructor you can do this but I would like to give
each object a different number, starting at 1 or 0, increasing 1 each
time a new object has been created...

The first object has automatically number 1 assigned to "intNumber" ,
the second number 2, etc...

I know this is possible but have forgotten how to do this ...

Many thanks

John