Variant Array Copy, Array row contains Object

[Neal Zimm]

Hi All,
For the first time I had a need to put an object inside a two dimension
variant array.

The proc below was for some initial testing.
I had to code an object test at the line marked with 1.

I was surprised that the 'copy' at line 2. worked.
Can you tell me why?

Thanks.
Neal Z.



Sub Test()
Dim vArray, vArrayB
Dim Row As Long, Col As Long

ReDim vArray(1 To 2, 1 To 2)

Set vArray(1, 1) = ActiveWorkbook
vArray(1, 2) = "abc"
vArray(2, 1) = 24
Set vArray(2, 2) = ActiveSheet

ReDim vArrayB(LBound(vArray, 1) To UBound(vArray, 1), _
LBound(vArray, 2) To UBound(vArray, 2))

For Row = LBound(vArray, 1) To UBound(vArray, 1)
For Col = LBound(vArray, 2) To UBound(vArray, 2)

If Not IsObject(vArray(Row, Col)) Then
vArrayB(Row, Col) = vArray(Row, Col)
Else
'1. for individual items, Set is needed, expected.
Set vArrayB(Row, Col) = vArray(Row, Col)
End If
Next Col
Next Row

' 2. Why does this not 'error out' ?
vArrayB = vArray
End Sub

 

[joel]

Basic knows how to copy an array. Basic is funny that things yo
expect to work will not work, and things you don't expect to work wil
work. Microsoft version of Basic is poorly documented and Microsof
implimented legacy features in other versions of Basic withou
documenting the features. I believe WANG originally developed Basic i
the 1970's and did a prettty good job of documenting the features of th
language. Microsft doesn't do a good job of documenting the VB
language so yo uare never sure what will work unless you try or kno
from experience.

 

[Peter T]

A shorter example

Sub test2()
Dim a(1), b()
Set a(1) = ThisWorkbook
b = a
Debug.Print b(1).Name
Debug.Print ObjPtr(ThisWorkbook), ObjPtr(a(1)), ObjPtr(b(1))
End Sub

Behind the scenes the object pointer stored in a(1) is copied to b(1)

Regards,
Peter T

 

[Neal Zimm]

Thanks Joel,
Sure is nice to know Excel VBA knows how to copy an entire array but
hiccoughs on one item in the array. LOL.

I know I'm dating myself here, but I know from first hand experience,
because I was there, that Basic was invented at Dartmouth College in the
early 1960's.
The head of the Math Department, John Kemeny, and another math professor
John Kurtz, along with some graduate students wrote it. (Interesting to note
that Kemeny later became president of Dartmouth, he was an absolutely
brilliant man.)
They gave it to General Electric, in exchange for which, GE gave
Dartmouth a couple of rooms full of computers. (They were a maker of big
mainframes back in the day...)
I don't know if you're old enough to remember the power plant accident
at Three Mile Island, but it you Google it, you may run into Kemeny's name
again as he headed up the Federal Commission which investigated the accident.

Thanks again,
Neal

 

[Neal Zimm]

Thanks again Peter,
It's the behind the scenes stuff that drives me a little bit crazy from
time to time.

 

[joel]

I don't remember GE being associatted with Basic. The first Basic
used was on a WANG computer into 1977 that had the language HARD-WIRE
into the computer. Some how the licensing got from GE to WNAG.
Searching the WEb there is a strong tie between the two companies. H
is a portion of an article from 1984


Article fromR Newswire Article date:April 10, 1984CopyrightCOPYRIGH
2009 PR Newswire Association LLC. This material is published unde
license from the publisher through the Gale Group, Farmington Hills
Michigan. All inquiries regarding rights or concerns about thi
content should be directed to customer service. (Hide copyrigh
information) Related articles

NEW YORK, April 10 /PRNewswire/ -- General Electric Informatio
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The company also announced a joint agreement with Wang Laboratories
Inc. that will allow users of the Wang Professional Computer to acces
GE Information Services' worldwide teleprocessing network and its offic
electronic mailbox service, the QUIK-COMM(TM) System.

"We are announcing a set of integrated capabilities that will enabl
corporations to better manage the information explosion taking place i
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president, GE Information Services. "The marketplace requires tha
corporations get at information when it is needed, where it is needed …