[arrays] Creating an Array from a Range in VBA

I'm having a seemingly basic problem but can't find any resources addressing it.

Simply put, I just want to load the contents of a Range of cells (all one column) into an Array.

I am able to accomplish this by means of

DirArray = Array(Range("A1"), Range("A2"))

But for some reason, I cannot create the array when expressed this way:

DirArray = Array(Range("A1:A2"))

My real Range is much longer (and may vary in length), so I don't want to have to individually enumerate the cells this way. Can anyone tell me how to properly load a whole Range into an Array?

With the latter code:

MsgBox UBound(DirArray, 1)

And

MsgBox UBound(DirArray)

Return 0, whereas with the former they return 1.

This function returns an array regardless of the size of the range.

Ranges will return an array unless the range is only 1 cell and then it returns a single value instead. This function will turn the single value into an array (1 based, the same as the array's returned by ranges)

This answer improves on previous answers as it will return an array from a range no matter what the size. It is also more efficient that other answers as it will return the array generated by the range if possible. Works with single dimension and multi-dimensional arrays

The function works by trying to find the upper bounds of the array. If that fails then it must be a single value so we'll create an array and assign the value to it.

Public Function RangeToArray(inputRange As Range) As Variant()
Dim size As Integer
Dim inputValue As Variant, outputArray() As Variant

    ' inputValue will either be an variant array for ranges with more than 1 cell
    ' or a single variant value for range will only 1 cell
    inputValue = inputRange

    On Error Resume Next
    size = UBound(inputValue)

    If Err.Number = 0 Then
        RangeToArray = inputValue
    Else
        On Error GoTo 0
        ReDim outputArray(1 To 1, 1 to 1)
        outputArray(1,1) = inputValue
        RangeToArray = outputArray
    End If

    On Error GoTo 0

End Function

Adding to @Vityata 's answer, below is the function I use to convert a row / column vector in a 1D array:

Function convertVecToArr(ByVal rng As Range) As Variant
'convert two dimension array into a one dimension array
    
    Dim arr() As Variant, slicedArr() As Variant
    arr = rng.value   'arr = rng works too (https://bettersolutions.com/excel/cells-ranges/vba-working-with-arrays.htm)
    
    If UBound(arr, 1) > UBound(arr, 2) Then
        slicedArr = Application.WorksheetFunction.Transpose(arr)
    Else
        slicedArr = Application.WorksheetFunction.index(arr, 1, 0)  'If you set row_num or column_num to 0 (zero), Index returns the array of values for the entire column or row, respectively._
                                                                   'To use values returned as an array, enter the Index function as an array formula in a horizontal range of cells for a row,_
                                                                   'and in a vertical range of cells for a column.
                                                                   'https://usefulgyaan.wordpress.com/2013/06/12/vba-trick-of-the-week-slicing-an-array-without-loop-application-index/
    End If
convertVecToArr = slicedArr
End Function

In addition to solutions proposed, and in case you have a 1D range to 1D array, i prefer to process it through a function like below. The reason is simple: If for any reason your range is reduced to 1 element range, as far as i know the command Range().Value will not return a variant array but just a variant and you will not be able to assign a variant variable to a variant array (previously declared).

I had to convert a variable size range to a double array, and when the range was of 1 cell size, i was not able to use a construct like range().value so i proceed with a function like below.

Public Function Rng2Array(inputRange As Range) As Double()

    Dim out() As Double    
    ReDim out(inputRange.Columns.Count - 1)

    Dim cell As Range
    Dim i As Long
    For i = 0 To inputRange.Columns.Count - 1
        out(i) = inputRange(1, i + 1) 'loop over a range "row"
    Next

    Rng2Array = out  
End Function

If we do it just like this:

Dim myArr as Variant
myArr = Range("A1:A10")

the new array will be with two dimensions. Which is not always somehow comfortable to work with:

To get away of the two dimensions, when getting a single column to array, we may use the built-in Excel function “Transpose”. With it, the data becomes in one dimension:

If we have the data in a row, a single transpose will not do the job. We need to use the Transpose function twice:

Note: As you see from the screenshots, when generated this way, arrays start with 1, not with 0. Just be a bit careful.

Using Value2 gives a performance benefit. As per Charles Williams blog

Range.Value2 works the same way as Range.Value, except that it does not check the cell format and convert to Date or Currency. And thats probably why its faster than .Value when retrieving numbers.

So

DirArray = [a1:a5].Value2

Bonus Reading

• Range.Value: Returns or sets a Variant value that represents the value of the specified range.
• Range.Value2: The only difference between this property and the Value property is that the Value2 property doesn't use the Currency and Date data types.