Increment an Array question

S

S G Booth

I'm searching up a column looking for a particular value.
When found, I need to add a range offset from that cell
to an array.
I find that the following code is overwriting varr(1) each
time....so the array never builds correctly
i = i + 1
If IsEmpty(varr(1)) Then
Set varr(1) = .Range("B" & StartRw)
Else
ReDim Preserve varr(1 To UBound(varr) + 1)
Set varr(UBound(varr)) = .Range("B" & StartRw)
End If

Why is the array not building correctly, please?

Regards
 
T

Tom Ogilvy

If can do two things
if the first element is empty, it writes the range value in the first
element.

otherwise, it increases the upperbound of the array by one and writes it in
the new element.


I am not sure what role "i" plays, but you increment that and don't use it.

If StartRw is not being incremented, then you would write the same value in
every element.

Not unless .Range("B" & StartRw) is empty and you are placing an empty value
in varr(1)
 
J

Jim Cone

SG,

You have to increment the Array.
I started from scratch and wrote something I think
is close to what you want? See if this is any help...
'-------------------------------------------------------

Sub AnotherTest()
Dim i As Long
Dim N As Long
Dim X As Long
Dim SearchRange As Excel.Range
Dim varr() As Double

Set SearchRange = Range(Cells(10, 1), Cells(Rows.Count, 1).End(xlUp))
N = SearchRange.Count
ReDim varr(1 To N)

For i = N To 1 Step -1
If SearchRange(i).Value = "Now Cough" Then
X = X + 1
varr(X) = SearchRange(i).Offset(0, 1).Value
End If
Next 'i
ReDim Preserve varr(1 To X)

'Just an example - as could run out of columns
Range(Cells(5, 4), Cells(5, 3 + X)).Value = varr()

Set SearchRange = Nothing
End Sub
'------------------------------------------------------------

Regards,
Jim Cone
San Francisco, USA
 
T

Tom Ogilvy

You have to increment the Array.
It does increment the array first.

Explain where you think the existing code does not work. Maybe my
explanation was flawed.

Since this is part of a bigger routine, starting form scratch is probably
not an option.
 
S

S G Booth

Have seen both your replies and Jim's. Thanks to you both. It is a segment
in a bigger series of routines.
I still cannot see the error(s).

Will try to create a simple set of data, with the relevent
code routine and post back.

Regards and thanks.
 
J

Jim Cone

Tom,

My remarks were addressed to SG.

If the Range assigned to the Varr(1) is blank, then it will be
evaluated as "IsEmpty" and will be overwritten on the next loop.

Regards,
Jim Cone
 
S

sali

S G Booth said:
Have seen both your replies and Jim's. Thanks to you both. It is a segment
in a bigger series of routines.
I still cannot see the error(s).
..

why do you need "isempty()"
at any moment simply use:
redim preserve varr(ubound(varr)+1)
varr(ubound)=...

when starting, use:
dim varr()
which is equal to "zero" length array, so, with first adding you should
create
your varr(1) ...

anyway, be aware of "option base 0/1"
 
T

Tom Ogilvy

by the way, my explanation was flawed. Since it is a set command, once
used, varr(1) can not be empty and will not be overwritten (at least with
the code you show - if you empty it somewhere else, then there is no
accounting for that).

as I recall, you were trying to identify pagebreaks, so apparently code that
you don't show prevents assignments as you expect. the code you show would
work as designed.
 
S

S G Booth

That was indeed your code, thanks, and it is still working fine for me.
This is a similar situation (re pages), but where the user has used a
routine to insert a page into the sheet.....I now need to revise the
Collection page(s) at the end of the sheet.
I'm trying to find where the first Collection page starts, and if there
are subsequent Collection pages, how many.

As before, each page starts with "Item" in Col1.
If it's the initial Collection page, then an offset from "Item"
Offset(1, 1).End(xlDown).Value should return "COLLECTION".
If it's a subsequent Collection then it'll be "COLLECTION (Cont.)".
Any other value should mean a normal data page.

In my test sheet I had "Item" in A1, A55, A114, A173.
I had "COLLECTION" in B58, and "COLLECTION (Cont.)"
in B117 and B176. To mark the end of the sheet, I used "£" in
F231.

Sub TestArray()
Dim C As Range, TargetCell As String
Dim myRng As Range, £Col As Integer
Dim LastRw As Long, ws As Worksheet
Dim StartRw As Long
Dim varr()

£Col = 6
Set ws = ActiveSheet
With ws
Set myRng = (.Cells(65536, £Col).End(xlUp) _
.Offset(0, -(£Col - 1)))
myRng.Select
LastRw = myRng.Row
ReDim varr(1 To 1)
Do 'Until
TargetCell = .Columns(1).Find(What:="Item", _
After:=ActiveCell, LookIn:=xlFormulas, _
LookAt:=xlPart, SearchOrder:=xlByRows, _
SearchDirection:=xlPrevious, _
MatchCase:=False).Select
If ActiveCell.Offset(1, 1).End(xlDown).Value _
= "COLLECTION" Then
'it should mean only one Collection page
StartRw = ActiveCell.Offset(1, 1) _
.End(xlDown).Row + 2
If IsEmpty(varr(1)) Then
Set varr(1) = .Range("B" & StartRw)
Else
ReDim Preserve varr(1 To UBound(varr) + 1)
Set varr(UBound(varr)) = .Range("B" & StartRw)
End If
ElseIf ActiveCell.Offset(1, 1).End(xlDown).Value = _
"COLLECTION (Cont.)" Then
'it should mean multiple Collections
StartRw = ActiveCell.Offset(1, 1) _
.End(xlDown).Row + 2
If IsEmpty(varr(1)) Then
Set varr(1) = .Range("B" & StartRw)
Else
ReDim Preserve varr(1 To UBound(varr) + 1)
Set varr(UBound(varr)) = .Range("B" & StartRw)
End If
ElseIf ActiveCell.Row = 1 Then
Exit Do
End If
Loop
End With
End Sub

For me it seems to overwrite varr(1) rather than increment the
array.....and I don't know why.

Any help much appreciated.

Regards.
 
T

Tom Ogilvy

Actually, I think this is an anomaly in the use of isempty.

Isempty checks if a variant variable has been initialized. The purpose of
the check in this code is to see whether varr(1) has been initialized and if
not assign the value to varr(1). If it has, then raise the upperbound and
assign it to the last item in the array. Unfortunately, since varr(1) is
being set as a reference to a range, if it does hold a range, then isempty
checks the situation for the range (is the range empty). So for a range
object, the correct test would be

if varr(1) is nothing then

however, if varr(1) has actually never been initialized (which was the real
purpose of the test) then this test will fail since only an object can be
checked with "is nothing"

To overcome this, I think you should alter your code to:

i = i + 1
If TypeName(varr(1)) = "Empty" Then
Set varr(1) = .Range("B" & StartRw)
Else
ReDim Preserve varr(1 To UBound(varr) + 1)
Set varr(UBound(varr)) = .Range("B" & StartRw)
End If

You can ignore my 2nd response that if a range is assigned it can't
evaluate to empty - I went crazy for a minute <g>. Hopefully this will fix
your problem. If not, post back.
 
S

S G Booth

Yes, seems to work fine now. Have only run it on the
Sub Test() code so far. Thanks also for the explanation.

I've sampled up the sheet to find the Collection pages
because they're at the end of each sheet...seemed quicker. However, the
array elements will now be in the
reverse order to their sequence in the sheet (varr(1) will
now be the very last Collection page).

Since I will wish to loop through the array elements, can
I do it in reverse order...something like a For Each and
Step -1 statement?

Regards and thanks.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top