What Does This Mean?

11 Dec 2006 2:01 AM

Herman Jones

I found this statement in some sample code. It seems to be syntactically
correct. What do the brackets around "String" mean?

Dim sWork As [String] = "Some number of characters"

11 Dec 2006 3:41 AM

Michael C

"Herman Jones" <HermanJo***@discussions.microsoft.com> wrote in message
news:6F3326FF-B08F-4729-A6AB-80AD27F9EA27@microsoft.com...
>I found this statement in some sample code. It seems to be syntactically
> correct. What do the brackets around "String" mean?
>
> Dim sWork As [String] = "Some number of characters"

They are used indicate the item in the brackets is not a keyword. For
example if you wanted to name a variable Dim you might be able to do this:

Dim [Dim] as Int32
[Dim] = 5

I'm not sure if that works but that the sort of thing it's used for. It
could be used for function names, class names etc. In the case of String
above it does nothing but doesn't cause any problems either. You can remove
them.

Michael

11 Dec 2006 4:20 AM

Herman Jones

This example seems to be a little different. In your example you're using
[Dim] as a variable name. It comes before the "As" keyword.

The sample code I found has [String] after the "As" keyword. I don't thing
that "String" is being used as the variable name because the program later
refers to the "sWork" variable.

Is it possible that the brackets have some other purpose when they bracket a
datatype?

Show quoteHide quote

"Michael C" wrote:

> "Herman Jones" <HermanJo***@discussions.microsoft.com> wrote in message
> news:6F3326FF-B08F-4729-A6AB-80AD27F9EA27@microsoft.com...
> >I found this statement in some sample code. It seems to be syntactically
> > correct. What do the brackets around "String" mean?
> >
> > Dim sWork As [String] = "Some number of characters"
>
> They are used indicate the item in the brackets is not a keyword. For
> example if you wanted to name a variable Dim you might be able to do this:
>
> Dim [Dim] as Int32
> [Dim] = 5
>
> I'm not sure if that works but that the sort of thing it's used for. It
> could be used for function names, class names etc. In the case of String
> above it does nothing but doesn't cause any problems either. You can remove
> them.
>
> Michael
>
>
>

11 Dec 2006 5:16 AM

Michael C

"Herman Jones" <HermanJo***@discussions.microsoft.com> wrote in message
news:2E9EE6D2-FEDB-4521-967F-12BB3C2C3203@microsoft.com...
> This example seems to be a little different. In your example you're using
> [Dim] as a variable name. It comes before the "As" keyword.
>
> The sample code I found has [String] after the "As" keyword. I don't
> thing
> that "String" is being used as the variable name because the program later
> refers to the "sWork" variable.
>
> Is it possible that the brackets have some other purpose when they bracket
> a
> datatype?

The dim was just 1 example, it can be used in many places. If a program had
a datatype called "As" then you'd need to do Dim x as [As]

Michael

11 Dec 2006 5:42 PM

Brian Gideon

Herman,

No, the bracket does not have alternate meaning when used with data
types. Brackets allow you to create escaped or verbatim identifiers.
This is useful when you need to refer to an identifier that is also a
keyword. The most common scenario is the interaction between different
programming languages. For example, a C# programmer may think Alias
would be a good choice for a property name not knowing that it is a
keyword in VB. A VB programmer would need to use brackets when
referring to that property.

Brian

Herman Jones wrote:
Show quoteHide quote

> This example seems to be a little different. In your example you're using
> [Dim] as a variable name. It comes before the "As" keyword.
>
> The sample code I found has [String] after the "As" keyword. I don't thing
> that "String" is being used as the variable name because the program later
> refers to the "sWork" variable.
>
> Is it possible that the brackets have some other purpose when they bracket a
> datatype?

11 Dec 2006 5:42 PM

Brian Gideon

Herman,

No, the bracket does not have alternate meaning when used with data
types. Brackets allow you to create escaped or verbatim identifiers.
This is useful when you need to refer to an identifier that is also a
keyword. The most common scenario is the interaction between different
programming languages. For example, a C# programmer may think Alias
would be a good choice for a property name not knowing that it is a
keyword in VB. A VB programmer would need to use brackets when
referring to that property.

Brian

Herman Jones wrote:
Show quoteHide quote

> This example seems to be a little different. In your example you're using
> [Dim] as a variable name. It comes before the "As" keyword.
>
> The sample code I found has [String] after the "As" keyword. I don't thing
> that "String" is being used as the variable name because the program later
> refers to the "sWork" variable.
>
> Is it possible that the brackets have some other purpose when they bracket a
> datatype?

11 Dec 2006 5:50 AM

Cor Ligthert [MVP]

>I found this statement in some sample code. It seems to be syntactically
> correct. What do the brackets around "String" mean?
>
> Dim sWork As [String] = "Some number of characters"

That the programmer of this program is probably an idiot.
You replace with this the general meaning of the keyword.

Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles MyBase.Load
        Dim a As New [String](1)
        Dim b As String = "What the hell is this"
    End Sub
End Class
Public Class [String]
    Public Sub New(ByVal b As Integer)
        b = b
    End Sub
    Public b As Integer
End Class

Cor

11 Dec 2006 6:04 AM

Michael C

"Cor Ligthert [MVP]" <notmyfirstn***@planet.nl> wrote in message
news:%237JZpfOHHHA.4056@TK2MSFTNGP03.phx.gbl...
>    Public Sub New(ByVal b As Integer)
>        b = b
>    End Sub
>    Public b As Integer

Does that actually work in vb.net?

Michael

11 Dec 2006 6:14 AM

Cor Ligthert [MVP]

It runs and gives very strange results.

Cor

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"Michael C" <nospam@nospam.com> schreef in bericht
news:OFxm6kOHHHA.3952@TK2MSFTNGP02.phx.gbl...
> "Cor Ligthert [MVP]" <notmyfirstn***@planet.nl> wrote in message
> news:%237JZpfOHHHA.4056@TK2MSFTNGP03.phx.gbl...
>>    Public Sub New(ByVal b As Integer)
>>        b = b
>>    End Sub
>>    Public b As Integer
>
> Does that actually work in vb.net?
>
> Michael
>

11 Dec 2006 6:40 AM

Michael C

"Cor Ligthert [MVP]" <notmyfirstn***@planet.nl> wrote in message
news:u%2390dtOHHHA.1248@TK2MSFTNGP03.phx.gbl...
> It runs and gives very strange results.

Would it just leave this.b = 0 or uninitialised?

Michael

11 Dec 2006 8:52 AM

Stephany Young

Try it and find out!

Show quoteHide quote

"Michael C" <nospam@nospam.com> wrote in message
news:%23mUCp4OHHHA.2456@TK2MSFTNGP06.phx.gbl...
> "Cor Ligthert [MVP]" <notmyfirstn***@planet.nl> wrote in message
> news:u%2390dtOHHHA.1248@TK2MSFTNGP03.phx.gbl...
>> It runs and gives very strange results.
>
> Would it just leave this.b = 0 or uninitialised?
>
> Michael
>

11 Dec 2006 5:04 PM

Cor Ligthert [MVP]

zero

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"Michael C" <nospam@nospam.com> schreef in bericht
news:%23mUCp4OHHHA.2456@TK2MSFTNGP06.phx.gbl...
> "Cor Ligthert [MVP]" <notmyfirstn***@planet.nl> wrote in message
> news:u%2390dtOHHHA.1248@TK2MSFTNGP03.phx.gbl...
>> It runs and gives very strange results.
>
> Would it just leave this.b = 0 or uninitialised?
>
> Michael
>

11 Dec 2006 4:44 PM

Herman Jones

I'm still a little confused, but it's getting clearer.

I've attached the entire code sample below. It's from
http://msdn2.microsoft.com/en-us/library/9yyz8a6c.aspx

As you can see, in this sample, there's no Class definition for [String].
It also does not use the "New" keyword as your example did.

I'm gussing that in this case VB is using the standard System.String even
though "String" is enclosed in brackets. Is this correct?

Option Explicit On
Option Strict On
Imports System
Imports System.IO
Public Class CharsFromStr
    Public Shared Sub Main()
        ' Create a string to read characters from.
        Dim str As [String] = "Some number of characters"
        ' Size the array to hold all the characters of the string
        ' so that they are all accessible.
        Dim b(24) As Char
        ' Create an instance of StringReader and attach it to the string.
        Dim sr As New StringReader(str)
        ' Read 13 characters from the array that holds the string, starting
        ' from the first array member.
        sr.Read(b, 0, 13)
        ' Display the output.
        Console.WriteLine(b)
        ' Close the StringReader.
        sr.Close()
    End Sub
End Class

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"Cor Ligthert [MVP]" wrote:

> >I found this statement in some sample code. It seems to be syntactically
> > correct. What do the brackets around "String" mean?
> >
> > Dim sWork As [String] = "Some number of characters"
>
> That the programmer of this program is probably an idiot.
> You replace with this the general meaning of the keyword.
>
> Public Class Form1
>     Private Sub Form1_Load(ByVal sender As System.Object, _
>     ByVal e As System.EventArgs) Handles MyBase.Load
>         Dim a As New [String](1)
>         Dim b As String = "What the hell is this"
>     End Sub
> End Class
> Public Class [String]
>     Public Sub New(ByVal b As Integer)
>         b = b
>     End Sub
>     Public b As Integer
> End Class
>
> Cor
>
>
>

12 Dec 2006 4:32 AM

_AnonCoward

"Herman Jones" <HermanJo***@discussions.microsoft.com> wrote in
message news:6F3326FF-B08F-4729-A6AB-80AD27F9EA27@microsoft.com...
:
: I found this statement in some sample code. It seems to be
: syntactically correct. What do the brackets around "String"
: mean?
:
: Dim sWork As [String] = "Some number of characters"

I don't see the point of using the brackets in this context. I checked
out the complete code you included in the other post and it compiles
just fine with or without the brackets. Just out of curiousity, I
compared both versions of the code in the ildasm utility and the vb
compiler emitted the exact same code. In this instance, the brackets
are meaningless. That said, brackets are quite useful. Indeed, they
are often necessary.

Let's say you have access to an email message class written in C#
which exposes the following Properties:

From
To
Subject
Body

If you were to declare an instance of this class in vb, you'd have a
problem because "To" is a vb keyword. The following would fail:

    With New CSharpEmailMessageType
      .From = "M*@MyDomain.com"
      .To = "Y**@YourDomain.com"
      .Subject = "Hello"
      .Body = "World"
    End With

This would not compile. To get around this, you would need to do the
following:

    With New CSharpEmailMessageType
      .From = "M*@MyDomain.com"
      .[To] = "Y**@YourDomain.com"
      .Subject = "Hello"
      .Body = "World"
    End With

Now the code would compile just fine. Brackets tell the compiler to
treat what would otherwise be a reserved keyword as any other code
element.

Another use I've personally found for the brackets is when I'm
generating throw away code. I don't post to this forum often, but
occasionally I will offer a code example to a question. In those
cases, I may post a complete example that will compile and run. For
example, I might do something like this:

    =======================================
    Option Strict

    Imports Microsoft.VisualBasic
    Imports System

    Public Module [module]
      Public Sub Main
        Dim c As New [class]
        Console.WriteLine(c.GetMessage)
      End Sub
    End Module

    Public Class [class]
      Public Function GetMessage() As String
        Return "Hello World" & vbCrLf
      End Function
    End Class
    =======================================

I defined a module and a class but really didn't want to waste time
trying to figure out a clever or relevant name for them, so I just
named them '[module]' and '[class]' and moved on from there.

Ralf

--
--
----------------------------------------------------------
*             ^~^                   ^~^                  *
*          _ {~ ~}                 {~ ~} _               *
*         /_``>*<                   >*<''_\              *
*        (\--_)++)                 (++(_--/)             *
----------------------------------------------------------
There are no advanced students in Aikido - there are only
competent beginners. There are no advanced techniques -
only the correct application of basic principles.

12 Dec 2006 6:09 AM

Cor Ligthert [MVP]

_Anon,

Nobody discuss that they can be handy. I do not believe that there is a
serious person who would give String another name even not somebody from who
is selling underwear.

Cor

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"_AnonCoward" <abc***@uvwxyz.com> schreef in bericht
news:yhqfh.5261$dD2.673@tornado.southeast.rr.com...
>
> "Herman Jones" <HermanJo***@discussions.microsoft.com> wrote in
> message news:6F3326FF-B08F-4729-A6AB-80AD27F9EA27@microsoft.com...
> :
> : I found this statement in some sample code. It seems to be
> : syntactically correct. What do the brackets around "String"
> : mean?
> :
> : Dim sWork As [String] = "Some number of characters"
>
>
> I don't see the point of using the brackets in this context. I checked
> out the complete code you included in the other post and it compiles
> just fine with or without the brackets. Just out of curiousity, I
> compared both versions of the code in the ildasm utility and the vb
> compiler emitted the exact same code. In this instance, the brackets
> are meaningless. That said, brackets are quite useful. Indeed, they
> are often necessary.
>
> Let's say you have access to an email message class written in C#
> which exposes the following Properties:
>
> From
> To
> Subject
> Body
>
>
> If you were to declare an instance of this class in vb, you'd have a
> problem because "To" is a vb keyword. The following would fail:
>
>    With New CSharpEmailMessageType
>      .From = "M*@MyDomain.com"
>      .To = "Y**@YourDomain.com"
>      .Subject = "Hello"
>      .Body = "World"
>    End With
>
> This would not compile. To get around this, you would need to do the
> following:
>
>    With New CSharpEmailMessageType
>      .From = "M*@MyDomain.com"
>      .[To] = "Y**@YourDomain.com"
>      .Subject = "Hello"
>      .Body = "World"
>    End With
>
> Now the code would compile just fine. Brackets tell the compiler to
> treat what would otherwise be a reserved keyword as any other code
> element.
>
> Another use I've personally found for the brackets is when I'm
> generating throw away code. I don't post to this forum often, but
> occasionally I will offer a code example to a question. In those
> cases, I may post a complete example that will compile and run. For
> example, I might do something like this:
>
>    =======================================
>    Option Strict
>
>    Imports Microsoft.VisualBasic
>    Imports System
>
>    Public Module [module]
>      Public Sub Main
>        Dim c As New [class]
>        Console.WriteLine(c.GetMessage)
>      End Sub
>    End Module
>
>    Public Class [class]
>      Public Function GetMessage() As String
>        Return "Hello World" & vbCrLf
>      End Function
>    End Class
>    =======================================
>
>
> I defined a module and a class but really didn't want to waste time
> trying to figure out a clever or relevant name for them, so I just
> named them '[module]' and '[class]' and moved on from there.
>
>
> Ralf
> --
> --
> ----------------------------------------------------------
> *             ^~^                   ^~^                  *
> *          _ {~ ~}                 {~ ~} _               *
> *         /_``>*<                   >*<''_\              *
> *        (\--_)++)                 (++(_--/)             *
> ----------------------------------------------------------
> There are no advanced students in Aikido - there are only
> competent beginners. There are no advanced techniques -
> only the correct application of basic principles.
>
>