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I have 2-dimensional array and I would like to inspect each element in a specific row with If-Then statements and assign assign values to the next row depending on the outcome of the If-Then statements? What is the correct syntax for looping through the elements of a row in a 2-d array?
Please, try using the next Sub:
Sub changeRow(arr As Variant, iR As Long, strTxt As String)
Dim i As Long
For i = LBound(arr, 2) To UBound(arr, 2) '(arr, 2) to determine the number of columns
arr(iR, i) = arr(iR, i) & strTxt
Next i
End Sub
Of course, it can be designed to do whatever you need on the respective row. Even extending parameters to be used.
It can easily be tested in the next way:
Sub testIterate2DArrayRow()
Dim sh As Worksheet, arr, arrR, iRow As Long, strAdd As String
Set sh = ActiveSheet
iRow = 2 'the array row to be iterated
strAdd = " - XX" 'string to be added to each row element (instructional example)
arr = sh.Range("A2:D6").value 'the easiest way to create a 2D array
arrR = Application.Index(arr, iRow, 0) 'create a 1D slice of the row to be iterated/modified
'if you need only iterating to extract something, you may stop here
'and iterate between its elements...
Debug.Print Join(arrR, "|") 'just to visually see the row content
changeRow arr, iRow, strAdd 'iterate on the iRow row (and modify something)
Debug.Print Join(Application.Index(arr, iRow, 0), "|") 'visual evidence of the modification...
End Sub
Edited:
I will let the above code for other people liking to learn the general concept.
Please, test the next code, which should process the array as (I understood) you need.
Its first lines only create the opportunity to easily check the concept. So, you should place the necessary bays on an Excel sheet, from "A1" to "J1" and run the above code. It will return the processed array starting from "L1":
Sub analizeBays()
Dim sh As Worksheet, BayRay(), i As Long
Set sh = ActiveSheet
BayRay = sh.Range("A1:J4").value 'only to easily test the concept
For i = LBound(BayRay, 2) To UBound(BayRay, 2)
If BayRay(1, i) <= 10 Then
BayRay(2, i) = 2035
BayRay(3, i) = 2005
BayRay(4, i) = 1005
ElseIf BayRay(1, i) > 10 And BayRay(1, i) <= 12 Then
BayRay(2, i) = 2022
BayRay(3, i) = 1032
BayRay(4, i) = 4344
End If
Next i
'drop the processed array content starting from "L1")
sh.Range("L1").Resize(UBound(BayRay), UBound(BayRay, 2)).value = BayRay
End Sub
Loop Through a Row of a 2D Array
Option Explicit
Sub LoopThroughRow()
Const RowIndex As Long = 2
Const Criteria As Double = 3
Const MinNum As Long = 1
Const MaxNum As Long = 5
' Populate with random integers.
Dim Data As Variant: ReDim Data(1 To 5, 1 To 5)
Dim r As Long, c As Long
For r = LBound(Data, 1) To UBound(Data, 1)
For c = LBound(Data, 2) To UBound(Data, 2)
Data(r, c) = Int((MaxNum - MinNum + 1) * Rnd + MinNum)
Next c
Next r
' Write criteria row.
For c = LBound(Data, 2) To UBound(Data, 2)
If Data(RowIndex, c) > Criteria Then
Data(RowIndex + 1, c) = "Yes"
Else
Data(RowIndex + 1, c) = "No"
End If
Next c
' Print result.
Debug.Print "Column", "Row " & RowIndex, "Row " & RowIndex + 1
For c = LBound(Data, 2) To UBound(Data, 2)
Debug.Print c, Data(RowIndex, c), Data(RowIndex + 1, c)
Next c
End Sub
Suppose I have a VBA one dimension array (or dict or collection) with X values. I need to perform an action with these values in batches of Y.
So if X = 55 and Y = 25, I would need to loop 3 times:
Pick values 1 to 25 and perform action
Pick values 26 to 50 and perform action
Pick last 5 values and perform action
Any ideas with good performance will be greatly appreciated :)
Edit:
I came up with the code below. It works although doesn't look very concise
Sub test()
Dim arr As Variant
Dim temparr As Variant
Dim sippno As Integer
Dim loopend As Integer
Dim loopstart As Integer
Dim batchsize As Integer
Dim i As Integer
'Storing main array with all values
arr = Sheet1.Range("A1:A" & Sheet1.Range("A" & Rows.Count).End(xlUp).Row).Value
'Setting count of values, batch size and starting step for loop
sippno = WorksheetFunction.CountA(arr)
loopstart = 1
batchsize = 10
Do Until sippno = 0
If sippno < batchsize Then
loopend = loopstart + sippno - 1
Else
loopend = loopstart + batchsize - 1
End If
ReDim temparr(loopstart To loopend)
For i = loopstart To loopend
temparr(i) = WorksheetFunction.Index(arr, i, 0)
sippno = sippno - 1
Next
loopstart = loopend + 1
'Action to be performed with batch of values stored in second array
Debug.Print WorksheetFunction.TextJoin(", ", True, temparr)
Loop
End Sub
Slicing via Application.Index()
Just for the sake of the art I demonstrate in this late post how to slice a 'vertical' array in one go into several 'flat' arrays in batches of e.g. 10 elements.
This approach benefits from the advanced rearranging features & pecularities of Application.Index()
allowing to pass entire row/column number arrays as arguments; here suffices a vertical array of desired row numbers, e.g. by filtering only rows 11 to 20 via Application.Index(data, Evaluate("Row(11:20)"), 0). .. c.f. see section 2 a)
Further notes:
evaluating a tabular row formula is one quick way to get consecutive row numbers.
transposing the function result changes the array dimension to a 1-dim array
reducing the array boundaries by -1 via ReDim Preserve ar(0 To UBound(ar) - 1) produces a zero-based array (optional)
Option Explicit
Sub splice()
Const batch = 10 ' act in units of 10 elements
With Sheet1
'1) get data (1-based 2-dim array)
Dim lastRow As Long
lastRow = .Cells(Rows.Count, "A").End(xlUp).Row
Dim data: data = .Range("A1:A" & lastRow).Value2
'2) slice
Dim i As Long, nxt As Long, ar As Variant
For i = 1 To UBound(data) Step batch
nxt = Application.min(i + batch - 1, UBound(data))
'2a) assign sliced data to 1- dim array (with optional redim to 0-base)
With Application
ar = .Transpose(.Index(data, Evaluate("row(" & i & ":" & nxt & ")")))
End With
'optional redimming to zero-base
ReDim Preserve ar(0 To UBound(ar) - 1)
'2b) perform some action
Debug.Print _
"batch " & i \ batch + 1 & ": " & _
"ar(" & LBound(ar) & " To " & UBound(ar) & ") ~~> " & _
Join(ar, "|")
Next
End With
End Sub
Slicing a 'flat' 1-dim array
If, however you want to slice a 1-dim array, like e.g. dictionary keys, it suffices to transpose the data input: data = Application.Transpose(...)
Option Explicit
Sub splice()
Const batch = 10
Dim data, ar()
Dim lastrow As Long, n As Long, i As Long
Dim j As Long, r As Long
With Sheet1
lastrow = .Cells(Rows.Count, "A").End(xlUp).Row
data = .Range("A1:A" & lastrow).Value2
End With
i = Int(lastrow / batch)
For n = 0 To i
r = batch
If n = i Then
r = lastrow Mod batch
End If
If r > 0 Then
ReDim ar(r - 1)
For j = 1 To r
ar(j - 1) = data(j + n * batch, 1)
Next
' do something
Debug.Print Join(ar, ",")
End If
Next
End Sub
2d array because to lazy to encode 1d but same idea with 1d:
Sub test()
arr = Sheet3.Range("A1").CurrentRegion.Value2
x = UBound(arr)
y = 5
jj = y
For j = 1 To UBound(arr)
sumaction = sumaction + arr(j, 1)
If (UBound(arr) - jj) < 0 Then
jj = UBound(arr)
sumaction = 0
End If
If j = jj Then
dosomething = sumaction * 2
sumaction = 0
jj = jj + y
End If
Next j
End Sub
I’m in a situation where I need to reproduce something in VBA and a bit stuck given my lack of understanding of object oriented language and VBA in general.
Problem:
I need to produce an array or vector based on a 2 column table.
The first range (column) contains unit counts.
The second range (column) contains numeric values.
I need to replicate the value based on the number of units.
For example,
if the first row contains 3 units with a value of $100
I need the array to contain $100, $100, $100.
This will need to be looped thru each row containing units.
So if row 2 contains 2 units with a value of $50
I need to complete array to be $100, $100, $100, $50, $50, and so on.
I understand this situation will require ReDim the array based on the total values. My struggle is I’ve been unable to figure out the nested for loops.
I get how to replicate the value based on the number of “units” like the below...
ReDim arr(0 To x - 1)
For i = 0 To x - 1
arr(i) = rng.Offset(0, 1).Value
Next
What is the best way to loop thru each row and replicate the values for each row in the range based on the unit count?
If anyone is familiar with R, I'm essentially looking for something that achieves the rep() function (e.g., rep(df$b, df$a)) and return the values in a single array.
Any help is greatly appreciated. Thanks
Or a one liner which uses the REPT function as you would have used in r :)
This assumes your data is in A1:B10 - the length can be made variable
s = Split(Join(Application.Transpose(Evaluate("=INDEx(REPT(B1:B10&"","",A1:A10),,1)"))), ",")
An an example, to dump the new to array to C1
s = Split(Join(Application.Transpose(Evaluate("=INDEx(REPT(B1:B10&"","",A1:A10),,1)"))), ",")
[c1].Resize(UBound(s), 1) = Application.Transpose(s)
When you say Row contains 3 units, do you mean the cell has value 3 or 3 Units? If it is 3 then you may not have to Redim the array in the loop. Simply find the sum of values in Col A which has units and Redim it in one go as shown below.
Sub Sample()
Dim ws As Worksheet
Dim Ar() As String
Dim n As Long, i As Long, lRow As Long
'~~> Change this to the relevant sheet
Set ws = Sheet6
With ws
n = Application.WorksheetFunction.Sum(.Columns(1))
ReDim Ar(t To n)
lRow = .Range("A" & .Rows.Count).End(xlUp).Row
n = 1
For i = 1 To lRow
If Len(Trim(.Range("A" & i).Value)) <> 0 Then
For j = 1 To .Range("A" & i).Value
Ar(n) = .Range("B" & i).Value
n = n + 1
Next j
End If
Next i
For i = LBound(Ar) To UBound(Ar)
Debug.Print Ar(i)
Next i
End With
End Sub
Screenshot
And if the cell has 3 Units then you will have to store the values of Col A in an array, do a replace on Unit/Units, find the sum and finally use the above code. Here is an example
Sub Sample()
Dim ws As Worksheet
Dim Ar() As String, tmpAr As Variant
Dim n As Long, i As Long, j As Long, k As Long, lRow As Long
'~~> Change this to the relevant sheet
Set ws = Sheet6
With ws
lRow = .Range("A" & .Rows.Count).End(xlUp).Row
tmpAr = .Range("A1:A" & lRow).Value
For i = LBound(tmpAr) To UBound(tmpAr)
tmpAr(i, 1) = Replace(tmpAr(i, 1), "Units", "")
tmpAr(i, 1) = Trim(Replace(tmpAr(i, 1), "Unit", ""))
n = n + Val(tmpAr(i, 1))
Next i
ReDim Ar(t To n)
n = 1
For i = 1 To lRow
If Len(Trim(.Range("A" & i).Value)) <> 0 Then
k = Val(Trim(Replace(Replace(.Range("A" & i).Value, "Units", ""), "Unit", "")))
For j = 1 To k
Ar(n) = .Range("B" & i).Value
n = n + 1
Next j
End If
Next i
For i = 1 To UBound(Ar)
Debug.Print Ar(i)
Next i
End With
End Sub
Screenshot
if your data is already in an array then ReDim'ing will delete it's contents. You can ReDim Preserve but it's an expensive operation, better to create a new array to put the results into.
I have assumed the data is contained within a Named Range called "Data" with Units being the first column and Values being the second column.
if your data changes regularly you can create a dynamic range using the OFFSET function i.e. =OFFSET(Sheet1!$A$1,0,0,COUNTA(Sheet1!$A:$A),2) assuming your data starts in cell A1 and there is no header row.
Sub ProcessData()
Dim DataArr() As Variant
Dim QtyColArr() As Variant
Dim ResultArr() As Variant
Dim TotalQty As Long
Dim i As Long, j As Long, k As Long
'store data into array
DataArr = Range("Data") 'assume data stored in named range called "Data"
'store Qty col into 1D array
QtyColArr = Range("Data").Resize(, 1)
'sum all qty vals
TotalQty = Application.Sum(QtyColArr)
're-size ResultsArray
ReDim ResultArr(1 To TotalQty)
'Initialize ResultsArr counter
k = LBound(ResultArr)
'loop DataArr
For i = LBound(DataArr) To UBound(DataArr)
'loop qty for current row
For j = 1 To DataArr(i, 1)
'copy value
ResultArr(k) = DataArr(i, 2)
'iterate ResultsArr counter
k = k + 1
Next j
Next i
'output to intermediate window
Debug.Print "{" & Join(ResultArr) & "}"
End Sub
I have an interesting problem. I need to fill in a 2D array with data, but I don't know how many data points there are until after the array is populated.
Dim finalArray(0 to 500000, 0 to 3)
R=0
For Each index in someDictionary
If Not someDictionary.item(index)(1) = 0
finalArray(R,0) = someDictionary.item(index)(1)
finalArray(R,1) = someDictionary.item(index)(2)
finalArray(R,2) = someDictionary.item(index)(3)
R = R + 1
End If
Next index
The issue is that I don't know how many items will be in the dictionary, nor how many will be nonzero. The only way I know is after I run the loop and have a count R.
Currently I'm printing the entire 500k row array to Excel, which is usually 100-400k rows of data with the rest blank. This is ungainly, and I would like to re-dimension the array to be the correct size. I can't use ReDim because I can't delete the data, and I can't use ReDim Preserve because it's 2-dimensional and I need to reduce the rows, not columns.
How about this?
Sub Sample()
Dim finalArray()
Dim R As Long
For Each Index In someDictionary
If Not someDictionary.Item(Index)(1) = 0 Then R = R + 1
Next Index
ReDim finalArray(0 To R, 0 To 3)
R = 0
For Each Index In someDictionary
If Not someDictionary.Item(Index)(1) = 0 Then
finalArray(R, 0) = someDictionary.Item(Index)(1)
finalArray(R, 1) = someDictionary.Item(Index)(2)
finalArray(R, 2) = someDictionary.Item(Index)(3)
R = R + 1
End If
Next Index
End Sub
You have a few options
Redim the array as needed rather then create up front (which I think is better than looping through the array twice :)). I have added this given your comment to tigeravatar
Transpose the array to redim the first dimension
Ignore the redundant data as per tigeravatar
Option 1
note I have flipped the data to make the point around testing for ReDim as you go rather than define an array size up front - it could well argue this changes the nature of the question but I thought the technique worth pointing out. Option2 shows how to transpose the array regardless
Sub SloaneDog()
Dim finalArray()
Dim R As Long
Dim lngCnt As Long
Dim lngCnt2 As Long
lngCnt = 100
ReDim finalArray(1 To 3, 1 To lngCnt)
somedictionary = Range("A1:C3001")
For lngCnt2 = 1 To UBound(somedictionary, 1)
finalArray(1, lngCnt2) = "data " & lngCnt2
If lngCnt2 Mod lngCnt = 0 Then ReDim Preserve finalArray(1 To 3, 1 To lngCnt2 + lngCnt)
Next
End Sub
Option 2
Sub EddieBetts()
Dim X()
Dim Y()
Dim LngCnt As Long
ReDim X(1 To 1000, 1 To 3)
Debug.Print UBound(X, 1)
LngCnt = 100
Y = Application.Transpose(X)
ReDim Preserve Y(1 To UBound(Y, 1), 1 To LngCnt)
X = Application.Transpose(Y)
Debug.Print UBound(X, 1)
End Sub
I'm using VB6 and I need to do a ReDim Preserve to a Multi-Dimensional Array:
Dim n, m As Integer
n = 1
m = 0
Dim arrCity() As String
ReDim arrCity(n, m)
n = n + 1
m = m + 1
ReDim Preserve arrCity(n, m)
Whenever I do it as I have written it, I get the following error:
runtime error 9: subscript out of range
Because I can only change the last array dimension, well in my task I have to change the whole array (2 dimensions in my example) !
Is there any workaround or another solution for this?
As you correctly point out, one can ReDim Preserve only the last dimension of an array (ReDim Statement on MSDN):
If you use the Preserve keyword, you can resize only the last array
dimension and you can't change the number of dimensions at all. For
example, if your array has only one dimension, you can resize that
dimension because it is the last and only dimension. However, if your
array has two or more dimensions, you can change the size of only the
last dimension and still preserve the contents of the array
Hence, the first issue to decide is whether 2-dimensional array is the best data structure for the job. Maybe, 1-dimensional array is a better fit as you need to do ReDim Preserve?
Another way is to use jagged array as per Pieter Geerkens's suggestion. There is no direct support for jagged arrays in VB6. One way to code "array of arrays" in VB6 is to declare an array of Variant and make each element an array of desired type (String in your case). Demo code is below.
Yet another option is to implement Preserve part on your own. For that you'll need to create a copy of data to be preserved and then fill redimensioned array with it.
Option Explicit
Public Sub TestMatrixResize()
Const MAX_D1 As Long = 2
Const MAX_D2 As Long = 3
Dim arr() As Variant
InitMatrix arr, MAX_D1, MAX_D2
PrintMatrix "Original array:", arr
ResizeMatrix arr, MAX_D1 + 1, MAX_D2 + 1
PrintMatrix "Resized array:", arr
End Sub
Private Sub InitMatrix(a() As Variant, n As Long, m As Long)
Dim i As Long, j As Long
Dim StringArray() As String
ReDim a(n)
For i = 0 To n
ReDim StringArray(m)
For j = 0 To m
StringArray(j) = i * (m + 1) + j
Next j
a(i) = StringArray
Next i
End Sub
Private Sub PrintMatrix(heading As String, a() As Variant)
Dim i As Long, j As Long
Dim s As String
Debug.Print heading
For i = 0 To UBound(a)
s = ""
For j = 0 To UBound(a(i))
s = s & a(i)(j) & "; "
Next j
Debug.Print s
Next i
End Sub
Private Sub ResizeMatrix(a() As Variant, n As Long, m As Long)
Dim i As Long
Dim StringArray() As String
ReDim Preserve a(n)
For i = 0 To n - 1
StringArray = a(i)
ReDim Preserve StringArray(m)
a(i) = StringArray
Next i
ReDim StringArray(m)
a(n) = StringArray
End Sub
Since VB6 is very similar to VBA, I think I might have a solution which does not require this much code to ReDim a 2-dimensional array - using Transpose, if you are working in Excel.
The solution (Excel VBA):
Dim n, m As Integer
n = 2
m = 1
Dim arrCity() As Variant
ReDim arrCity(1 To n, 1 To m)
m = m + 1
ReDim Preserve arrCity(1 To n, 1 To m)
arrCity = Application.Transpose(arrCity)
n = n + 1
ReDim Preserve arrCity(1 To m, 1 To n)
arrCity = Application.Transpose(arrCity)
What is different from OP's question: the lower bound of arrCity array is not 0, but 1. This is in order to let Application.Transpose do it's job.
Note that Transpose is a method of the Excel Application object (which in actuality is a shortcut to Application.WorksheetFunction.Transpose). And in VBA, one must take care when using Transpose as it has two significant limitations: If the array has more than 65536 elements, it will fail. If ANY element's length exceed 256 characters, it will fail. If neither of these is an issue, then Transpose will nicely convert the rank of an array form 1D to 2D or vice-versa.
Unfortunately there is nothing like 'Transpose' build into VB6.
In regards to this:
"in my task I have to change the whole array (2 dimensions"
Just use a "jagged" array (ie an array of arrays of values). Then you can change the dimensions as you wish. You can have a 1-D array of variants, and the variants can contain arrays.
A bit more work perhaps, but a solution.
I haven't tested every single one of these answers but you don't need to use complicated functions to accomplish this. It's so much easier than that! My code below will work in any office VBA application (Word, Access, Excel, Outlook, etc.) and is very simple. Hope this helps:
''Dimension 2 Arrays
Dim InnerArray(1 To 3) As Variant ''The inner is for storing each column value of the current row
Dim OuterArray() As Variant ''The outer is for storing each row in
Dim i As Byte
i = 1
Do While i <= 5
''Enlarging our outer array to store a/another row
ReDim Preserve OuterArray(1 To i)
''Loading the current row column data in
InnerArray(1) = "My First Column in Row " & i
InnerArray(2) = "My Second Column in Row " & i
InnerArray(3) = "My Third Column in Row " & i
''Loading the entire row into our array
OuterArray(i) = InnerArray
i = i + 1
Loop
''Example print out of the array to the Intermediate Window
Debug.Print OuterArray(1)(1)
Debug.Print OuterArray(1)(2)
Debug.Print OuterArray(2)(1)
Debug.Print OuterArray(2)(2)
I know this is a bit old but I think there might be a much simpler solution that requires no additional coding:
Instead of transposing, redimming and transposing again, and if we talk about a two dimensional array, why not just store the values transposed to begin with. In that case redim preserve actually increases the right (second) dimension from the start. Or in other words, to visualise it, why not store in two rows instead of two columns if only the nr of columns can be increased with redim preserve.
the indexes would than be 00-01, 01-11, 02-12, 03-13, 04-14, 05-15 ... 0 25-1 25 etcetera instead of 00-01, 10-11, 20-21, 30-31, 40-41 etcetera.
As long as there is only one dimension that needs to be redimmed-preserved the approach would still work: just put that dimension last.
As only the second (or last) dimension can be preserved while redimming, one could maybe argue that this is how arrays are supposed to be used to begin with.
I have not seen this solution anywhere so maybe I'm overlooking something?
(Posted earlier on similar question regarding two dimensions, extended answer here for more dimensions)
You can use a user defined type containing an array of strings which will be the inner array. Then you can use an array of this user defined type as your outer array.
Have a look at the following test project:
'1 form with:
' command button: name=Command1
' command button: name=Command2
Option Explicit
Private Type MyArray
strInner() As String
End Type
Private mudtOuter() As MyArray
Private Sub Command1_Click()
'change the dimensens of the outer array, and fill the extra elements with "1"
Dim intOuter As Integer
Dim intInner As Integer
Dim intOldOuter As Integer
intOldOuter = UBound(mudtOuter)
ReDim Preserve mudtOuter(intOldOuter + 2) As MyArray
For intOuter = intOldOuter + 1 To UBound(mudtOuter)
ReDim mudtOuter(intOuter).strInner(intOuter) As String
For intInner = 0 To UBound(mudtOuter(intOuter).strInner)
mudtOuter(intOuter).strInner(intInner) = "1"
Next intInner
Next intOuter
End Sub
Private Sub Command2_Click()
'change the dimensions of the middle inner array, and fill the extra elements with "2"
Dim intOuter As Integer
Dim intInner As Integer
Dim intOldInner As Integer
intOuter = UBound(mudtOuter) / 2
intOldInner = UBound(mudtOuter(intOuter).strInner)
ReDim Preserve mudtOuter(intOuter).strInner(intOldInner + 5) As String
For intInner = intOldInner + 1 To UBound(mudtOuter(intOuter).strInner)
mudtOuter(intOuter).strInner(intInner) = "2"
Next intInner
End Sub
Private Sub Form_Click()
'clear the form and print the outer,inner arrays
Dim intOuter As Integer
Dim intInner As Integer
Cls
For intOuter = 0 To UBound(mudtOuter)
For intInner = 0 To UBound(mudtOuter(intOuter).strInner)
Print CStr(intOuter) & "," & CStr(intInner) & " = " & mudtOuter(intOuter).strInner(intInner)
Next intInner
Print "" 'add an empty line between the outer array elements
Next intOuter
End Sub
Private Sub Form_Load()
'init the arrays
Dim intOuter As Integer
Dim intInner As Integer
ReDim mudtOuter(5) As MyArray
For intOuter = 0 To UBound(mudtOuter)
ReDim mudtOuter(intOuter).strInner(intOuter) As String
For intInner = 0 To UBound(mudtOuter(intOuter).strInner)
mudtOuter(intOuter).strInner(intInner) = CStr((intOuter + 1) * (intInner + 1))
Next intInner
Next intOuter
WindowState = vbMaximized
End Sub
Run the project, and click on the form to display the contents of the arrays.
Click on Command1 to enlarge the outer array, and click on the form again to show the results.
Click on Command2 to enlarge an inner array, and click on the form again to show the results.
Be careful though: when you redim the outer array, you also have to redim the inner arrays for all the new elements of the outer array
I stumbled across this question while hitting this road block myself. I ended up writing a piece of code real quick to handle this ReDim Preserve on a new sized array (first or last dimension). Maybe it will help others who face the same issue.
So for the usage, lets say you have your array originally set as MyArray(3,5), and you want to make the dimensions (first too!) larger, lets just say to MyArray(10,20). You would be used to doing something like this right?
ReDim Preserve MyArray(10,20) '<-- Returns Error
But unfortunately that returns an error because you tried to change the size of the first dimension. So with my function, you would just do something like this instead:
MyArray = ReDimPreserve(MyArray,10,20)
Now the array is larger, and the data is preserved. Your ReDim Preserve for a Multi-Dimension array is complete. :)
And last but not least, the miraculous function: ReDimPreserve()
'redim preserve both dimensions for a multidimension array *ONLY
Public Function ReDimPreserve(aArrayToPreserve,nNewFirstUBound,nNewLastUBound)
ReDimPreserve = False
'check if its in array first
If IsArray(aArrayToPreserve) Then
'create new array
ReDim aPreservedArray(nNewFirstUBound,nNewLastUBound)
'get old lBound/uBound
nOldFirstUBound = uBound(aArrayToPreserve,1)
nOldLastUBound = uBound(aArrayToPreserve,2)
'loop through first
For nFirst = lBound(aArrayToPreserve,1) to nNewFirstUBound
For nLast = lBound(aArrayToPreserve,2) to nNewLastUBound
'if its in range, then append to new array the same way
If nOldFirstUBound >= nFirst And nOldLastUBound >= nLast Then
aPreservedArray(nFirst,nLast) = aArrayToPreserve(nFirst,nLast)
End If
Next
Next
'return the array redimmed
If IsArray(aPreservedArray) Then ReDimPreserve = aPreservedArray
End If
End Function
I wrote this in like 20 minutes, so there's no guarantees. But if you would like to use or extend it, feel free. I would've thought that someone would've had some code like this up here already, well apparently not. So here ya go fellow gearheads.
This is more compact and respect the intial first position in array and just use the inital bound to add old value.
Public Sub ReDimPreserve(ByRef arr, ByVal size1 As Long, ByVal size2 As Long)
Dim arr2 As Variant
Dim x As Long, y As Long
'Check if it's an array first
If Not IsArray(arr) Then Exit Sub
'create new array with initial start
ReDim arr2(LBound(arr, 1) To size1, LBound(arr, 2) To size2)
'loop through first
For x = LBound(arr, 1) To UBound(arr, 1)
For y = LBound(arr, 2) To UBound(arr, 2)
'if its in range, then append to new array the same way
arr2(x, y) = arr(x, y)
Next
Next
'return byref
arr = arr2
End Sub
I call this sub with this line to resize the first dimension
ReDimPreserve arr2, UBound(arr2, 1) + 1, UBound(arr2, 2)
You can add an other test to verify if the initial size is not upper than new array. In my case it's not necessary
Easiest way to do this in VBA is to create a function that takes in an array, your new amount of rows, and new amount of columns.
Run the below function to copy in all of the old data back to the array after it has been resized.
function dynamic_preserve(array1, num_rows, num_cols)
dim array2 as variant
array2 = array1
reDim array1(1 to num_rows, 1 to num_cols)
for i = lbound(array2, 1) to ubound(array2, 2)
for j = lbound(array2,2) to ubound(array2,2)
array1(i,j) = array2(i,j)
next j
next i
dynamic_preserve = array1
end function
Function Redim2d(ByRef Mtx As Variant, ByVal QtyColumnToAdd As Integer)
ReDim Preserve Mtx(LBound(Mtx, 1) To UBound(Mtx, 1), LBound(Mtx, 2) To UBound(Mtx, 2) + QtyColumnToAdd)
End Function
'Main Code
sub Main ()
Call Redim2d(MtxR8Strat, 1) 'Add one column
end sub
'OR
sub main2()
QtyColumnToAdd = 1 'Add one column
ReDim Preserve Mtx(LBound(Mtx, 1) To UBound(Mtx, 1), LBound(Mtx, 2) To UBound(Mtx, 2) + QtyColumnToAdd)
end sub
If you not want include other function like 'ReDimPreserve' could use temporal matrix for resizing. On based to your code:
Dim n As Integer, m As Integer, i as Long, j as Long
Dim arrTemporal() as Variant
n = 1
m = 0
Dim arrCity() As String
ReDim arrCity(n, m)
n = n + 1
m = m + 1
'VBA automatically adapts the size of the receiving matrix.
arrTemporal = arrCity
ReDim arrCity(n, m)
'Loop for assign values to arrCity
For i = 1 To UBound(arrTemporal , 1)
For j = 1 To UBound(arrTemporal , 2)
arrCity(i, j) = arrTemporal (i, j)
Next
Next
If you not declare of type VBA assume that is Variant.
Dim n as Integer, m As Integer