I know you can easily take a range of cells and slap them into a Variant Array but I want to work with a string array (because it's single-dimensional and takes less memory than a Variant array).
Is there any way to automatically convert a range into a string array?
Right now I am using a function that will take the range and save the values in a variant array, then convert the variant array to a string array. It works nice , but I'm looking for a way to go directly from the range to string array. Any help would be greatly appreciated.
Function RangeToArray(ByVal my_range As Range) As String()
Dim vArray As Variant
Dim sArray() As String
Dim i As Long
vArray = my_range.Value
ReDim sArray(1 To UBound(vArray))
For i = 1 To UBound(vArray)
sArray(i) = vArray(i, 1)
Next
RangeToArray = sArray()
End Function
UPDATE:
It's looking like there is no way to skip the step of throwing the data into a variable array first before converting it to a single-dimensional string array. A shame if it's true (even if it doesn't take much effort, I like to ultra-optimize so I was hoping there was a way to skip that step). I'll close the question in a few days if no solution presents itself. Thanks for the helpful comments, guys!
UPDATE2:
Answer goes to Simon who put in great effort (so did everyone else) and utlimately pointed out it's indeed impossible to go from range to string array in one shot. Thanks, everyone.
You actually can go directly from a range to an array using the functions Split, Join and a delimiter not in the text.
Assuming you have already assigned a 1D range of values as SrcRange
Dim Array() As String: Array = Split(Join(Application.Transpose(SrcRange), "#"), "#")
How about...
Public Function RangeToStringArray(theRange As Excel.Range) As String()
' Get values into a variant array
Dim variantValues As Variant
variantValues = theRange.Value
' Set up a string array for them
Dim stringValues() As String
ReDim stringValues(1 To UBound(variantValues, 1), 1 To UBound(variantValues, 2))
' Put them in there!
Dim columnCounter As Long, rowCounter As Long
For rowCounter = UBound(variantValues, 1) To 1 Step -1
For columnCounter = UBound(variantValues, 2) To 1 Step -1
stringValues(rowCounter, columnCounter) = CStr(variantValues(rowCounter, columnCounter))
Next columnCounter
Next rowCounter
' Return the string array
RangeToStringArray = stringValues
End Function
Function RangeToStringArray(myRange as range) as String()
ReDim strArray(myRange.Cells.Count - 1) As String
Dim idx As Long
Dim c As Range
For Each c In myRange
strArray(idx) = c.Text
idx = idx + 1
Next c
RangeToStringArray = strArray
End Function
If you don't mind altering the contents of the clipboard then:
COPY the range to the clipboard with the Copy method:
MyTargetRange.Copy
Copy the contents from the clipboard to a string variable (search this site or elsewhere for functions to transfer strings to/from the clipboard).
SPLIT the string into a variant array:
MyStringArray = Split(MyClipboardText, vbCrLf)
OPTIONAL: The array will have one additional blank element because there is always an additional Return (vbCrLf) at the end of the text you just copied to the clipboard. To remove simply resize the array:
Redim Preserve MyStringArray(Ubound(MyStringArray) - 1)
Very simple and quick!!!
Drawbacks are that the clipboard may change when you least expect it (during a recalculation) and that it only produces arrays of strings (not Doubles or other numerical value types).
This would be EXTREMELY HELPFUL if you are working with lots of repetitive functions (thousands) that use the same data (thousands of data points). The first time your function is called, do all the intermediate calculations on the ranges of data that you need but save the results in static variables. Also save a string copy of your input ranges via the clipboard. With each subsequent call to your function, convert the input ranges to text, again via the clipboard, and compare with the saved copy. If they are the same you may be able to bypass allot of your preliminary calculations.
Named ranges used in VBA are already arrays. So first make the range into a named range, then refer to it and delete the named range.
For example:
ThisWorkbook.Names.Add Name:="test_array", RefersTo:=Sheet1.Range("A4:B10")
a = Sheet1.Range("test_array")
ThisWorkbook.Names("test_array").Delete
Related
I have a column of data with unique strings where the first 4 characters in the string may be a repeat of the first 4 characters in another string, in a format similar to:
ABCDEF
ABCDXY
ABCDKL
DTYTZF
DTYTSD
I am attempting to loop through this data to identify which 4 starting characters appear more then three times. If the first 4 digits of the string occur 3 times or more, I would like to remove these from the array entirely, and end up with an array that excludes these values. For example, in my column above, as 3 strings or more begin with 'ABCD', I would like to remove all strings that begin with this code, and have only every other value remain, such that my result would be:
DTYTZF
DTYTSD
I am currently looping through the array, pushing any value that occurs three times or more into a NEW array, and plan to then use that list to do a second pass on the original array, and remove any matches. This may not be the most efficient way, but I've not been able to determine a better way that is guaranteed not to mess my data up.
I have worked through looping through the strings to identify which strings occur more then once, but when I try to push them to an array, the string successfully is pushed to the array, but is then replaced with the next value as soon as it is pushed to the array. I know the value is pushed correctly, because if I view the array immediately afterwards, I see the value in the array. When the next value is pushed and you view the array again, only the new value is displayed (The older ones are not).
I believe this is due to my limited understanding of ReDim-ing arrays, and me not fully understanding a code snippet for pushing this value into an array. My (condensed) code is as follows:
Sub pickupValues()
Dim valuesArray()
Dim i As Long
Dim y As Long
Dim sizeCheck As Long
Dim tempArray() As String
valuesArray() = Worksheets("Sheet1").Range("A1:A10").Value
For i = LBound(valuesArray) To UBound(valuesArray)
sizeCheck = 0
For y = LBound(valuesArray) To UBound(valuesArray)
If Left(valuesArray(i, 1), 4) = Left(valuesArray(y, 1), 4) Then
sizeCheck = sizeCheck + 1
i = y
If sizeCheck >= 3 Then
ReDim tempArray(1 To 1) As String 'I'm not sure why I need to do this.
tempArray(UBound(tempArray)) = Left(valuesArray(i, 1), 4) 'I believe this is what pushes the value into the array.
ReDim Preserve tempArray(1 To UBound(tempArray) + 1) As String 'Again unsure on what the purpose of this is.
viewArray (tempArray)
End If
End If
Next y
Next i
End Sub
Function viewArray(myArray)
Dim txt As String
Dim i As Long
For i = LBound(myArray) To UBound(myArray)
txt = txt + myArray(i) + vbCrLf
Next i
MsgBox txt
End Function
What am I doing wrong?
I would like to re-use the same basic code later in the function to push other values OUT of an array based on if they match the string or not, but it seems VBA does not like to move values out of arrays either. Is there an easy solution that would match both scenarios?
I've rewritten what you are trying to do. I'm using the filter function to quickly get your results in the array
Option Explicit
Public Sub pickupValues()
Dim tmp As Variant
Dim results As Variant
Dim i As Long
Dim v
' Make sure this matches your range
With ThisWorkbook.Sheets("Sheet1")
' Important to transpose the input here as Filter will only take a 1D array. Even though it's only 1 column, setting an array this way will generate a 2D array
tmp = Application.Transpose(.Range(.Cells(1, 1), .Cells(.Cells(.Rows.Count, 1).End(xlUp).Row, 1)).Value2)
End With
' ReDiming to the maximum value and slimming down afterwards is much quicker then increasing your array each time you've found a new value
ReDim results(1 To UBound(tmp))
For Each v In tmp
' Less then 2 as first result is '0'. Will return '-1' if can't be found but as test criteria is in the array it will always be at least 0
If UBound(Filter(tmp, Left(v, 4))) < 2 Then
i = i + 1
results(i) = v
End If
Next v
' Redim Preserve down to actual array size
If i > 0 Then
ReDim Preserve results(1 To i)
viewArray (results)
Else
MsgBox "Nothing Found"
End If
End Sub
' Should really be a sub as doesn't return anything back to caller
Public Sub viewArray(myArray)
MsgBox Join(myArray, vbCrLf)
End Sub
Your algorithm is not helping you.
Option 1:
Sort your array. Then you can make a single pass to find sequential values with the same first four characters and count them.
Option 2:
Use a Dictionary object: first four characters as key, number of occurrences as value.
Problem: I am comparing two columns of names. If a name from the primary column matches a name in the secondary column, then I would like to add the matching name to an array of strings.
Function 1: This boolean function should indicate whether there is a match:
Function Match(name As String, s As Worksheet, column As Integer) As Boolean
Dim i As Integer
i = 2
While s.Cells(i, column) <> ""
If s.Cells(i, column).Value = name Then
Match = True
End If
i = i + 1
Wend
Match = False
End Function
Function 2: This function should add the matching name to a dynamic array of strings. Here I am somewhat stuck as I am new to arrays- any suggestions?
Function AddToArray(ys) As String()
Dim a() As String
Dim size As Integer
Dim i As Integer
Dim sh As Worksheet
Dim rw As Range
size = 0
ReDim Preserve a(size)
For Each rw In sh.Rows
If Match(sh.Cells(rw.Row, 1), s, column) = True Then
??
size = size + 1
End Function
Here is one solution. I scrapped your Match function and replaced it with a Find function.
Option Explicit
Sub AddToArray()
Dim primaryColumn As Range, secondaryColumn As Range, matchedRange As Range
Dim i As Long, currentIndex As Long
Dim matchingNames As Variant
With ThisWorkbook.Worksheets("Sheet1")
Set primaryColumn = .Range("A1:A10")
Set secondaryColumn = .Range("B1:B10")
End With
'Size your array so no dynamic resizing is necessary
ReDim matchingNames(1 To primaryColumn.Rows.Count)
currentIndex = 1
'loop through your primary column
'add any values that match to the matchingNames array
For i = 1 To primaryColumn.Rows.Count
On Error Resume Next
Set matchedRange = secondaryColumn.Find(primaryColumn.Cells(i, 1).Value)
On Error GoTo 0
If Not matchedRange Is Nothing Then
matchingNames(currentIndex) = matchedRange.Value
currentIndex = currentIndex + 1
End If
Next i
'remove unused part of array
ReDim Preserve matchingNames(1 To currentIndex - 1)
'matchingNames array now contains just the values you want... use it how you need!
Debug.Print matchingNames(1)
Debug.Print matchingNames(2)
'...etc
End Sub
Extra comments
There is no need to create your own Match function because it already exists in VBA:
Application.Match()
WorksheetFunction.Match()
and as I mentioned above you can also achieve the same result with the Find function which is my preference here because I prefer the way you can check for no matches (other methods throw less convenient errors).
Finally, I also opted to restructure your code into one Sub rather than two Functions. You weren't returning anything with your AddToArray function which pretty much means by definition it should actually be a Sub
As I stated in a comment to the question, there are a couple of problems in your code before adding anything to the array that will prevent this from working, but assuming that this was caused by simplifying the code to ask the question, the following should work.
The specific question that you are asking, is how to populate the array while increasing its size when needed.
To do this, simply do this:
Instead of:
ReDim Preserve a(size)
For Each rw In sh.Rows
If Match(sh.Cells(rw.Row, 1), s, column) = True Then
Reorder this so that it is:
For Each rw In sh.Rows
If Match(sh.Cells(rw.Row, 1), s, column) = True Then
ReDim Preserve a(size) 'increase size of array
a(size) = sh.Cells(rw.Row,1) 'put value in array
size = size + 1 'create value for size of next array
End If
Next rw
....
This probably isn't the best way to accomplish this task, but this is what you were asking to do. First, increasing the array size EVERY time is going to waste a lot of time. It would be better to increase the array size every 10 or 100 matches instead of every time. I will leave this exercise to you. Then you could resize it at the end to the exact size you want.
I have created a UDF that merges various value, range and array inputs into a single array.
Hitting ctrlshiftenter enters it as an array formula meaning VALUE(F4:G4) returns an array {1,#VALUE}.
My formula stitches values (5, "cat"), ranges ("F6","B2:D6") and even arrays like the one returned by Value(), and outputs an array. In the image example that is
{0.283982519688569,0.161633595994901,0.521865473646119,0.675542592903341,0.119984734979722,0.842918190377968,0.882045093468071,0.57708164295789,0.305844376489788,0.365360349735221,0.131686453379672,0.557018723742854,0.511032693705543,0.746174410924489,0.863516943921978,5,"cat","Dog",1,#VALUE!}
Here's the code:
Public Function PROBABLY(ParamArray inputArray() As Variant) As Variant
'Takes a list of parameters, the first of which is an integer, and
Dim inElement As Variant
Dim outputArray() As Variant
Dim subcell As Variant
'convert ranges to values
'creating a new array from the mixture of ranges and values in the input array
ReDim outputArray(0)
For Each inElement In inputArray
'Normal values get copied from the input UDF to an output array, ranges get split up then appended
If TypeName(inElement) = "Range" Or TypeName(inElement) = "Variant()" Then
For Each subcell In inElement
outputArray(UBound(outputArray)) = subcell
ReDim Preserve outputArray(UBound(outputArray) + 1)
Next subcell
'Stick the element on the end of an output array
Else
outputArray(UBound(outputArray)) = inElement
ReDim Preserve outputArray(UBound(outputArray) + 1)
End If
Next inElement
ReDim Preserve outputArray(UBound(outputArray) - 1)
PROBABLY = outputArray
End Function
That was just to show the versatility of the formula with various inputs, in reality I do not want to use this in array formulae. =PROBABLY(B2:D6,5,"cat") could be entered normally, without ctrlshiftenter. But the issue is that this returns a Variant() -specifically an array*, which makes it hard to use with non array formulae, which often require a Range input. So =CONCAT(PROBABLY(B2:D6,5)) works fine, but SUMIF(PROBABLY(B2:D6,5),">.5") does not work, as SUMIF() requires a range input. Same reason SUMIF(VALUE(1,2),">.5") doesn't work, like my function, value returns an array.
So the question: can I trick Excel into thinking my array is a range, format it as a Range in some way. Obviously I could take the code out of the UDF and into a sub, then paste my array into a temporary spreadsheet range and tell excel to reference that, but I was hoping to keep the UDF wrapper. (I don't think I can edit the worksheet from within a UDF, although is there some hidden space where I can paste the array and access it from a formula?
Thinking aloud there, any better insights?
*hence () after Variant
I can use an un-dimensioned String array with the Split() function to read fields from a String, but apparently, a String array has to be dimensioned to use it in a loop.
Why is that, and are there other situations where an array does not need to be dimensioned?
Dim field() As String
field = Split(data_line, "~")
Dim pref_line(10) As String
Input #1, pref_line(i)
but apparently, a String array has to be dimensioned to use it in a loop.
When use an un-dimensioned String array with the Split() function, the array is automatically dimensioned and values assigned to it. Also you can use that in a loop using For i = LBound(field) to UBound(field)
Option Explicit
Sub Sample()
Dim field() As String
Dim data_line As String
data_line = "aaa~bbb"
field = Split(data_line, "~")
Debug.Print field(0)
End Sub
Are there other situations where an array does not need to be dimensioned?
Yes. When you do not know how many items needs to be added to an array then you declare and un dimensioned array and Redim Preserve it to add values. For example
Option Explicit
Sub Sample()
Dim field() As Long
Dim n As Long, i As Long
ReDim Preserve field(n)
For i = 1 To 100
field(n) = i
n = n + 1
ReDim Preserve field(n)
Next i
End Sub
Split() returns its own array regardless of what you defined before. You are effectively overwriting the value of your variable.
Dim field() As String declares an array, but does not allocate it.
Dim pref_line(10) As String both declares and allocates it.
field = Split(data_line, "~") both allocates an array and populates it.
Others have already answered your question, and correctly about what you asked for. So I won't comment on that.
On a side note, you should avoid Redimming arrays as much as possible. Do that only when absolutely necessary. Remember that it is just one line of code for us, but a whole lot of work for the runtime engine. First find a new contiguous memory location for the new array; then copy the array items from the old to new one; then discard the old array. So you see one Redim Preserve statement produces how much work for the compiler.
For this reason, redimming inside a loop is "usually" a bad idea, since you know in advance how many times the loop will run and how many elements you will have in the end. So in such cases, redim your array before the start of loop, rather than doing it inside the loop. The end result would be a better performance :)
Taking the code in #SiddharthRout 's reply as an example, notice that the Loop will produce 100 items since you are looping from 1 to 100. So instead of ReDim Preserve field(n) inside the loop, move that outside it before the start of loop. ReDim Preserve field(100) as Long, or simply ReDim field(100) as Long.
I want to have an array list in vba, hence I have a variant declared in excel vba like:
Dim Students(10) as variant
Now I want to store numbers in Students list. the numbers are not continuous. Sometime like:
Students(2,7,14,54,33,45,55,59,62,66,69)
How can I do this in vba? also how can I access the list items?
Students must be declared as a dynamic array. That is, an array whose bounds can be changed. Dim Students(10) gives an array whose bounds cannot be changed and cannot be loaded from an array.
Dim Students() As Variant
To load Students:
Students = Array(2,7,14,54,33,45,55,59,62,66,69)
To access the elements:
Dim Inx As Long
For Inx = LBound(Students) to UBound(Students)
Debug.Print Students(Inx)
Next
LBound (Lower bound) and UBound mean that the for loop adjusts to the actual number of elements in Students.
This is too complex for you right now, and you'll probably never run into a situation where you'll need this, but:
I use the following method for forming more memory-efficient arrays (because Variant uses the most memory of any variable type) while still having the convenience of declaring the array contents in one line. To follow your example:
Dim Students() As Long
Dim Array2() As String
Array2() = Split("2,7,14,54,33,45,55,59,62,66,69", ",")
ReDim Array1(0) As Long
For Loop1 = LBound(Array2()) To UBound(Array2())
ReDim Preserve Array1(0 To (UBound(Array1) + 1)) As String
Array1(Loop1) = Array2(Loop1)
Next Loop1
ReDim Preserve Array1(0 To (UBound(Array1) - 1)) As Long
Erase Array2
An example of accessing it would be something like:
For Loop1 = LBound(Students) to UBound(Students)
Msgbox Students(Loop1)
Next Loop1
I learned this from here: http://www.vbforums.com/showthread.php?669265-RESOLVED-VBA-Excel-Assigning-values-to-array-in-a-single-line&p=4116778&viewfull=1#post4116778
You can add values to an Array like this...
For i = 1 to 10
Students(i) = i
Next i
Or like this
Students = Array(2,7,14,54,33,45,55,59,62,66,69)
Then you can access the values in the same manor. Note if you use the second option you'll need to declare it as follows:
Dim Students() As Variant
Well,
That depends on how you would supply the values for the array, would you get the values from Worksheet.Range or from TextBox or ListBox , But basically the code would be something like that :
Dim students(10) as Integer
Dim Carrier as Integer
For i = LBound(students) To UBound(Students)
'some code to get the values you want to from whatever is your source
'then assign the value to Carrier
students(i)=Carrier
Next i
It is not good practice to dim an array as Variant when you certainly know that you are going to use integers only, as it will eat alot of memory that is not needed in the first place.
You also should be aware of the bounds of the numbers that are going to be assigned, if it exceeds the Integer limit then you should use Double or Float.
This is my first participation in the site,Cheers.