Hi,

I've created a fairly complex object model and would like to define an
array

example: Public property dummyarray(1 to 100) as single

as a public property for the object, but if I've understood correctly VB 5
does not support that kind of object interfaces.

I've tried two different workarounds

1. Define a local property and a property Get function that returns a
specific element of the array

example:

Private property localdummyarray(1 to 100) as single

Property Get dummyarray(index) as single
        dummyarray = localdummyarray(index)
end property

2. Define a class eg. (arrayclass) which contains the property, property
Get function described in 1. and then define an object type property in the
real class.

Example:

Class: ArrayClass

Private property localdummyarray(1 to 100) as single

Property Get dummyarray(index) as single
        dummyarray = localdummyarray(index)
end property
...

Class: RealClass

Public property realarray as new ArrayClass

Both of these workarounds work but are about 10 times slower to use than
conventional arrays. Since speed is crucial in my project I've would be
really grateful if someone would know of a better workaround.

Tony

Tony:
I'm not sure what a 'conventional' array is (a local one?), but there are
several ways to reference data in a class module.  It is possible to make your
array a variant and thereby reference it as a public 'property' of the class -
this is frowned on generally because it exposes data directly to the owner app,
but if your 'property get' just does a simple assignment, what's the dif?
Check this out:
' SomeClass
Option Explicit
Public SomeArray As Variant
Private SngArray(1 To 100) As Single
Public Property Get EntireArray() As Variant
  EntireArray = SomeArray
End Property
Public Property Get OneMember(Index As Integer) As Single
  OneMember = SomeArray(Index)
End Property
Public Property Get UpperBoundOfArray() As Integer
  UpperBoundOfArray = UBound(SngArray)
End Property
Private Sub Class_Initialize()
Dim i As Integer
ReDim SomeArray(1 To 100)
For i = 1 To 100
  SngArray(i) = i * 1.1
Next i
SomeArray = SngArray
End Sub

If I instantiate SomeClass, I can reference any element of this array with
SomeClass.SomeArray(x), SomeClass.EntireArray(x), or SomeClass.OneMember(x).
I can also retrieve ubound(SomeClass.SomeArray), ubound(SomeClass.EntireArray)
and, of course, UpperBoundOfArray.  For retrieving a single element or for
walking through the array, OneMember must be fastest, but if you need to pass
the array to some other function, EntireArray does the trick.  (I'm really
uncomfortable using SomeArray for the above reasons, but I've also seen some
evidence that going through the Property Get will be faster than the direct
access anyway!)

Does this help?

Oops - The line
Redim SomeArray(1 to 100)
in the class_initialize is, of course, useless/senseless/meaningless . . .

Worse than that. I should give you an error because your original Dim
SomeArray(1 To 100) made it a static array that can't be resized.

--
Myrna Larson