Hi!

This sounds probably quite silly, but I just can't figure out this one.
Consider the following which lets "a" be an array with 0 elements:

Dim a() As Integer
a = New Integer() {}

Now what do I have to code if I want an empty array as default value in
a function? This one doesn't work:

Function test(Optional ByVal a As Integer() = New Integer() {})
End Function

It says: Constant expression required. Is this not possible in general
because default values can only be simple types?

Greets and thanks,
Urs

"Urs van Binsbergen" <ego-(E-Mail Removed)> schrieb
> This sounds probably quite silly, but I just can't figure out this
> one. Consider the following which lets "a" be an array with 0
> elements:
>
> Dim a() As Integer
> a = New Integer() {}
>
> Now what do I have to code if I want an empty array as default value
> in a function? This one doesn't work:
>
> Function test(Optional ByVal a As Integer() = New Integer() {})
> End Function
>
> It says: Constant expression required. Is this not possible in
> general because default values can only be simple types?

Yes. Add an overloaded version:

Function test()
Test(New Integer() {})
End Function


--
Armin

Urs,
In addition to the overload that Armin used.

Seeing as the parameter is an Optional array, consider using a ParamArray
instead:

Function Test(ByVal ParamArray a() As Integer) As Integer
End Function

Then when you call it, passing no parameters you will get an empty array.

Dim x As Integer
x = Test()

Passing a list of intergers you will get an array of integers.

x = Test(1,2,3,4,5)

Passing an array of integers you will get that array of integers.

Dim a() As Integer = {1,2,3,4,5}
x = Test(a)

Hope this helps
Jay

"Urs van Binsbergen" <ego-(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi!
>
> This sounds probably quite silly, but I just can't figure out this one.
> Consider the following which lets "a" be an array with 0 elements:
>
> Dim a() As Integer
> a = New Integer() {}
>
> Now what do I have to code if I want an empty array as default value in
> a function? This one doesn't work:
>
> Function test(Optional ByVal a As Integer() = New Integer() {})
> End Function
>
> It says: Constant expression required. Is this not possible in general
> because default values can only be simple types?
>
> Greets and thanks,
> Urs
>