As a noobie to VBA, I am having a Hell of a time understanding how arrays, dynamic arrays in specific, work. I am an Industrial Engineering student, so most of my coding has been done with MatLab.
My question is: Why do I keep getting Run-time error '9' "Subscript out of range" for the following code:
Sub FunWithArrays()
Dim DynArray()
Dim i As Integer
Dim j As Integer
j = 1
For i = 1 To 10
DynArray(j) = i
j = j + 1
ReDim DynArray(UBound(DynArray) + 1)
MsgBox DynArray(i)
Next
End Sub
Any and all help is appreciated!
As people in the comments have mentioned, dynamic arrays are just that: dynamic. That is to say that if you declare an array without dimension, as you have here with Dim DynArray() then it doesn't at this point have any "slots" to store anything.
When an array is declared this way, you then need to Redim it to tell it how many slots you want it to have (presumably after determining this from some other data or user input).
The full code for this would be:
Sub FunWithArrays()
Dim DynArray()
Dim i As Integer
Dim j As Integer
j = 1
Redim DynArray(10)
' redimensioned the array to hold 10 items (since
' you've set the loop as i=1 to 10 you must already
' know that the array wants to hold 10 things)
For i = 1 To 10
'ReDim Preserve DynArray(i)
' this is how you could do it if you didn't know in
' advance that you were going to loop 10 times,
' but as somebody else said, this is a slow way to do it.
DynArray(i) = j
j = j + 1
MsgBox DynArray(i)
' Generally instead of a messagebox here I would use:
' Debug.Print DynArray(i)
' this then prints out the value (on a new line each time)
' into the immediate window which means you can see the
' output without having to click "OK" each time.
Next
End Sub
You can also redimension the array within the loop, or later on, to hold a different number of items, but if you want to keep the items already stored in the array you must use ReDim:
ReDim Preserve DynArray(i)
It's also good practice in general to declare the array type. When you use Dim DynArray() this creates an array of type Variant which can hold anything (String, Double, Object, etc.). If you explicitly declare the type e.g. Dim DynArray() as Integer then it'll only allocate enough memory to hold integers, which is more efficient. For many applications the difference in speed will not make a difference, but when you're dealing with looping through something thousands of times it can matter.
Related
I have a "Datevarie" dynamic matrix which contains many dates.
At some point in the routine I have to extract from DateVarie the lowest value.
The problem is that when I use the Lbound function, I always return the value 1 instead of the date (for example "01/01/2018").
I think the data in the array is entered correctly as I debugged it step by step several times.
How can I resolve without having to report data on a sheet and order them? Do I have to use FOR ... NEXT? The dates can be 2-3 but also several tens
Type interventi
...
data as date
...
public Intervento as interventi
public rs1 as adodb.recordset
...
Sub TheSubWithProblem(...)
...
dim Datevarie() as date
..
redim preserve etc..
DateVarie(k)=format(RS1!DataI,"dd/mm/yyyy") '<<<< correct
...
Intervento.data=lbound(datevarie) '<<<< always return 1
...
The problem is that when I use the Lbound function, I always return the value 1 instead of the date (for example "01/01/2018").
LBOUND and UBOUND functions return the lower- and upper bounds of the array, not the lowest and highest values within the array.
Arrays in VBA are base-0 by default, so an initialized array should typically have LBound of 0.
If you want to get the lowest or highest value, then you need to implement your own algorithm to do so (e.g., a for/next loop), or if this is a single-dimensional array we can potentially make use of an ArrayList object which has (among other things) a Sort method:
Set d = CreateObject("System.Collections.ArrayList")
Dim dateVarie As Variant
Dim i As Long, m As Long, day As Long
For i = 1 To 100
m = Application.WorksheetFunction.RandBetween(1, 12)
day = Application.WorksheetFunction.RandBetween(1, 30)
d.Add (DateValue(DateSerial(2018, m, day)))
Next
'Preserve your un-sorted array, if needed:
ReDim dateVarie(d.Count - 1)
dateVarie = d.ToArray()
Msgbox "The first value is: " & dateVarie(0)
d.Sort ' Sorts the arraylist:
MsgBox "The lowest value is: " & (d(0))
Arrays start at 0. This is why the below returns 0:
Sub TestMe()
Dim datevarie(2) As Date
Debug.Print LBound(datevarie)
End Sub
And it does not matter, whether you put values in the array or not.
If you want an array to start at 1, in VBA write Option Base 1 and make sure that noone sees the code, because you may have problems with your colleagues/peers:
Option Explicit
Option Base 1
Sub TestMe()
Dim datevarie(2) As Date
Debug.Print LBound(datevarie)
End Sub
I am in need of help, I am trying to get all three columns of my multi column list box in a for loop, it should be pretty simple but I cannot figure it out,
I have googled for hours and to be honest haven't gotten anywhere as everyone wants it to be able to select and then loop through where as i just want to loop through all of them and take them to separate strings,
Hope this makes sense,
Thank you,
You can cycle through entries in the list by using the script below and fill a new array which can be pasted to an assigned range on the sheet of the same size as the array
dim arrayctr as integer, i as integer, myarray() as variant
With mylistbox
'below sizes array to size of list in listbox.
'use arrctr to populate selected items to array without blank entries in between.
redim myarray(1 to .listcount, 1 to 1) as variant
'.listcount gives total entries, but list starts from 0 so use i-1 to get values
For i = 1 to .listcount
if .selected(i-1) = true then myarray(arrayctr) = .list(i-1): _
arrctr = arrctr + 1
Next i
End with
you can use For next loop through entries and use Exit For when the value of the array = "" so it handles only entries with data in and avoids pointless calculations.
I have had similar troubles with finding online answers to some questions such as this, I hope it helps!
My research shows that I need to use Visual Basic. I am a programmer/developer, but have never used VB so if anyone could dumb it down it would be appreciated.
Here's my working excel function:
=IF(MATCH(1,E1:DP1,0),D1,FALSE)
I want to loop a few of those numbers such that:
=IF(MATCH(141,E1:DP378,0),D378,FALSE)
THEN take my answers (which will be strings, because column D are all strings, the rest of the excel file are numbers)
=CONCAT
end goal: have 141 String arrays populated based on the data in my table.
I went ahead and made my first attempt at VBA like this:
Sub myFunc()
'Initialize Variables
Dim strings As Range, nums As Integer, answer() As Variant, listAnswers() As Variant
'set variables
strings = ("C1:C378")
nums = 141
i = 0
j = 0
ReDim Preserve answer(i)
ReDim Preserve listAnswers(j)
'answer() = {""}
'for each in nums
For counter = 0 To nums
ReDim Preserve listAnswers(0 To j)
'set each list of answers
listAnswers(i) = Join(answer(), "insertJSONcode")
j = j + 1
'for each in Stings
For Each cell In strings
If cell <> "" Then
ReDim Preserve answer(0 To i)
answer(i) = 'essentially this: (MATCH(2,E1:DP1,0),D1,FALSE)
i = i + 1
end If
next cell 'end embedded forEach
Next LCounter 'end for loop
'is this possible? or wrong syntax?
Range("A:A").Value = listAnswers() ' should print 141 arrays from A1 to A141
End Sub
EDIT:
Important note I do NOT need to call the sheet by Name. I've successfully written integer values to by excel sheet in column A without doing so.
Also, the VBA I wrote I was never intended to work, I know it's broken at least where answer(i) is supposed to write to something. I'm only putting that code there to show I was able to at least able to get into spitting distance of the proper logic and prove I've put some serious effort into solving the problem and give a rough starting point.
Here's an image of the excel format. Column C goes down to 378 and the numbers listed from E through DP are populated by a database. It consists of blank cells and numbers between 1 and 141.
Looking back at my if statement:
=IF(MATCH(2,E2:DP2,0),D2,FALSE)
If I were to type that exactly into cell B2 it would output the correct answer "text2". which is neat and all, but I need every instance of text 2 written out, then CONCAT those results. Easy so far, I could drag that down all the way through column B and have all of my "text" strings in one column, CONCAT that column and there's the answer. However I don't just need #2, I need each number between 1 and 141. Plus I want to avoid writing 141 columns with a CONCAT on top of each one.
I've been messing around with VBA in Excel a bit recently; and as a small project for myself, I'm trying to create a "draw names from a hat" sort of macro.
I began by generating a random number, and then choosing which entry from a Table (i.e. ListObject) would be selected using a case statement. The problem with this is that it only works of the number of Table entries is always the same.
So my question (probably a ridiculous one) is: is it possible at all to generate a dynamic 'Select Case' block, where the number of cases on the block is based on the number of entries in the Table?
Thanks.
-Sean
Edit: To clarify: what I am trying to do, exactly, is this:
I generate a random number, i, from 1 to n=10*(number of Table entries). After this, I want to display, in a cell, one of the table entries based on the random number.
Ideally, the code would work similarly to this:
if i = 1 to 10 then choose event 1
if i = 11 to 20 then choose event 2
if i = 21 to 30 then choose event 3
...
if i = (n-9) to n then choose event (n/10)
I hope this helps to clarify the goal of the code.
From our comments here is something you can use:
Sub random()
Dim used_rows As Integer
Dim random As Integer
Dim cell_array() As Integer
used_rows = Sheet1.UsedRange.Rows.Count
ReDim cell_array(used_rows)
For i = 1 To used_rows
cell_array(i - 1) = Cells(i, 1)
Next
random = Int(Rnd * (used_rows))
MsgBox cell_array(random)
End Sub
You can go ahead and change MsgBox to whatever you like, or set like Cell(1,4).Value = cell_array(random), or however you'd like to proceed. It will be based off the number of rows used. Though depending on how you implement your spreadsheet the code might have to be changed a bit.
Here's the update code from the suggestions from the comments. Also remember to use Randomize() in your form initialization or WorkBook Open functions.
Sub random()
Dim used_rows As Integer
Dim random As Integer
'Multiple ways to get the row count, this is just a simple one which will work for most implementations
used_rows = Sheet1.UsedRange.Rows.Count
random = Int(Rnd * (used_rows))
'I use the variable only for the reason that you might want to reference it later
MsgBox Cells(random, 1)
End Sub
This assumes that by "table" you mean "Table with a capital T", known in VBA as a ListObject:
Sub PickRandomTens()
Dim lo As Excel.ListObject
Dim ListRowsCount As Long
Dim RandomNumber As Long
Dim ListEvent As String
Dim Tens As Long
Set lo = ActiveSheet.ListObjects(1)
ListRowsCount = lo.DataBodyRange.Rows.Count
RandomNumber = Application.WorksheetFunction.RandBetween(10, ListRowsCount * 10)
ListEvent = lo.ListColumns("Data Column").DataBodyRange.Cells(Int(RandomNumber / 10))
MsgBox "Random number: " & RandomNumber & vbCrLf & _
"Event: " & ListEvent
End Sub
In the situation where the user select two non-contiguous column ranges i wrote the following:
Dim count long
Dim points variant
Dim i long
Set user_range = ActiveWindow.RangeSelection
count = user_range.count / 2
ReDim points(1 To count, 1 To 2)
For i = 1 To count
MsgBox "value is" & user_range.Areas.Item(1).Value(i,1)
points(i, 1) = user_range.Areas.Item(1).Value(i,1)
points(i, 2) = user_range.Areas.Item(2).Value(i,1)
Next i
But i get an object error when i try this. Am i indexing Value wrong?
This should work right? Is there an easier way to do this?
Any help is greatly appreciated!
Thanks,
Russ
I'm afraid your code does not compile. First of all, you need to declare your variables correctly. You should also use Option Explicit.
Option Explicit
Dim count As Long
Dim points As Variant
Dim i As Long
Dim user_range As Range
The count and ReDim lines are OK, but you are assuming that the two selections are both the same size. Will that always be the case?
Then I'm not sure what it is you want to do, but I'm guessing you just want to save the values in user_range into points.
You need to adress them a bit different:
points(i, 1) = user_range.Areas(1).Cells(i, 1).Value 'Selection 1
points(i, 2) = user_range.Areas(2).Cells(i, 1).Value 'Selection 2