API reference · Arrays

FillColumn

Replace an existing column with values from a positional column vector.

FunctionArrays→VariantSource L807

Signature#

Function FillColumn(ByVal vArr As Variant, ByVal vColumn As Variant, ByVal lIndex As Long) As Variant

Parameters#

Parameter	VBA type	Default	Description
`vArr`	`Variant`ByVal	Required	Allocated 1D or 2D destination array. A 1D destination is expanded to one column before replacement.
`vColumn`	`Variant`ByVal	Required	Allocated 1D vector or a 2D single-column array with exactly as many rows as the destination. Row bounds may differ.
`lIndex`	`Long`ByVal	Required	Actual destination-column subscript. For an expanded 1D destination, this must be 1.

Returns#

Variant containing a new 2D array with the expanded destination's bounds. Returns Empty for non-array arguments, unsupported rank, invalid column index, a multi-column replacement, or a row-count mismatch.

Example#

SEE THE TRANSFORMATIONReplace column 2

Before

transactions2D · 2 × 2

Rows 1..2 · Columns 1..2

row / col	1	2
1	“Invoice A”	100
2	“Invoice B”	200

Additional input

corrected1D · (2,)

Indices 0..1 · one dimension

0	1
110	220

After

result2D · 2 × 2

Rows 1..2 · Columns 1..2

row / col	1	2
1	“Invoice A”	110
2	“Invoice B”	220

Values change; shape and bounds stay the same. The original matrix is unchanged.

Shaded headers are array indices, not data. Quoted cells are text. Values shown are derived from the source, not an Excel execution.

Sub ExampleFillColumn()
    Dim a As New Arrays
    Dim transactions As Variant, corrected As Variant, result As Variant

    ReDim transactions(1 To 2, 1 To 2)
    transactions(1, 1) = "Invoice A": transactions(1, 2) = 100
    transactions(2, 1) = "Invoice B": transactions(2, 2) = 200
    corrected = VBA.Array(110, 220)
    result = a.FillColumn(transactions, corrected, 2)
    Debug.Print result(1, 1), result(1, 2) ' Expected: Invoice A, 110
    Debug.Print transactions(1, 2)       ' Expected: 100; source unchanged
End Sub

Behavior and edge cases#

This replaces an existing column. It does not add a new column; use InsertColumns to append one.
1D arguments are interpreted vertically by DimExpand. A 2D single-row replacement with several columns is rejected rather than treated as a vertical vector.
Row counts must agree, but row lower bounds need not. Copying maps the first replacement row to the first destination row by positional offset.
The destination's row and column bounds are preserved after any 1D expansion. All non-target columns retain their original values.
The original destination and replacement arrays are not modified.

Performance#

O(r × c) time and O(r × c) output storage for r rows and c columns, plus any O(r) temporary column expansions.

View implementation

Function FillColumn(ByVal vArr As Variant, ByVal vColumn As Variant, ByVal lIndex As Long) As Variant
    'Fills a specified column using a 1D or 2D column vector

    Dim vArr_Out                As Variant
    Dim lRow                    As Long
    Dim lCol                    As Long
    Dim lSourceRow              As Long
    Dim lSourceCol              As Long

    If Not IsArray(vArr) Or Not IsArray(vColumn) Then Exit Function
    If Me.DimCounter(vArr) = 1 Then vArr = Me.DimExpand(vArr)
    If Me.DimCounter(vArr) <> 2 Then Exit Function
    If Me.DimCounter(vColumn) = 1 Then vColumn = Me.DimExpand(vColumn)
    If Me.DimCounter(vColumn) <> 2 Then Exit Function

    If lIndex < LBound(vArr, 2) Or lIndex > UBound(vArr, 2) Then Exit Function
    If LBound(vColumn, 2) <> UBound(vColumn, 2) Then Exit Function
    If UBound(vColumn, 1) - LBound(vColumn, 1) <> UBound(vArr, 1) - LBound(vArr, 1) Then Exit Function

    ReDim vArr_Out(LBound(vArr, 1) To UBound(vArr, 1), LBound(vArr, 2) To UBound(vArr, 2))
    lSourceCol = LBound(vColumn, 2)

    For lRow = LBound(vArr, 1) To UBound(vArr, 1)
        lSourceRow = LBound(vColumn, 1) + lRow - LBound(vArr, 1)
        For lCol = LBound(vArr, 2) To UBound(vArr, 2)
            If lCol = lIndex Then
                vArr_Out(lRow, lCol) = vColumn(lSourceRow, lSourceCol)
            Else
                vArr_Out(lRow, lCol) = vArr(lRow, lCol)
            End If
        Next lCol
    Next lRow

    FillColumn = vArr_Out
End Function