CODEWITHSUNDEEP
arraysdelphivariant
durumdara
durumdara

Reputation: 3473

Can a variant array have 0 elements?

The normal dynamic array supports empty (= nil, Length() = 0).

The variant array however does not seem to support this.

I pass my data in variant array (because of OLE/COM), and I get an error when the user defines 0 elements...

I can use varEmpty instead of a 0 length array, but these data arrays are flexible changed (add item, remove item, etc.).

How I can I pass empty arrays in a Variant, or do I need to use other way?

Upvotes: 7

Views: 920

Answers (2)

Lingo
Lingo

Reputation: 1

Here is some code that will update a Variant Array whether the Array is empty or not.

Sub Variant_Add(Var_Array As Variant, What)
    ' Add "What" to a "Var_Array" without book keeping.
    ' 3/18/19 Created, Mac Lingo

    ' Note: Variant_Add must be defined in the following way: _
        Dim Var_Array as Variant

    Prog = "Variant_Add"

    If IsEmpty(Var_Array) Then
        ReDim Var_Array(1) As Variant
        Knt = 1
    Else
        Knt = Var_Array(0) + 1
        ReDim Preserve Var_Array(Knt) As Variant
    End If

    Var_Array(Knt) = What
    Var_Array(0) = Knt

End Sub ' Variant_Add

Upvotes: 0

David Heffernan
David Heffernan

Reputation: 613013

varEmpty is the correct way to handle this. Of course, the code on the other side of the COM interface may not like empty arrays, but that all depends on the particular contract you have with that interface.

Upvotes: 5

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