Excel VBA: Range to String Array in 1 step

22
votes

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.

5
arraysstringexcelvbarange
There are direct memory manipulation routines you can access in VBA to create a very efficient function to convert the array. I don't have the time and skills to whip one up, though I do have some memory mapping code in my main application, so it's out there, and will help you make an extremely efficient array copying program. – Lance Roberts
The link to an answer I gave with some of the memory functions in it is here. – Lance Roberts
Although I wasn't able to apply the info in your links to this particular problem, it was a good read and interesting. Thanks for the link. – aevanko

5 Answers

11
votes

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), "#"), "#")
10
votes

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
3
votes
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
2
votes

If you don't mind altering the contents of the clipboard then:

  1. COPY the range to the clipboard with the Copy method:

    MyTargetRange.Copy

  2. Copy the contents from the clipboard to a string variable (search this site or elsewhere for functions to transfer strings to/from the clipboard).

  3. SPLIT the string into a variant array:

    MyStringArray = Split(MyClipboardText, vbCrLf)

  4. 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.

0
votes

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