API reference · Arrays

DimSplit

Convert a 2D matrix into a 1D outer array containing one 1D array per row.

FunctionArrays→VariantSource L304

Signature#

Function DimSplit(ByVal vArr As Variant) As Variant

Parameters#

Parameter	VBA type	Default	Description
`vArr`	`Variant`ByVal	Required	Allocated two-dimensional array to split into row arrays.

Returns#

Variant containing a 1D outer array with the source row bounds. Every inner 1D row array has the source column bounds. Returns Empty for non-arrays or unsupported rank.

Example#

SEE THE TRANSFORMATIONSplit into separate row vectors

Before

transactions2D · 2 × 2

Rows 1..2 · Columns 1..2

row / col	1	2
1	“Sales”	100
2	“Fees”	12

After

rows1D outer · (2,)

Outer indices 1..2 · each element is a 1D array

Element 11D · (2,)

1	2
“Sales”	100

Element 21D · (2,)

1	2
“Fees”	12

The outer array has rank 1. Its elements contain independent 1D row arrays, not a second rectangular dimension.

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

Sub ExampleDimSplit()
    Dim a As New Arrays
    Dim transactions As Variant, rows As Variant

    ReDim transactions(1 To 2, 1 To 2)
    transactions(1, 1) = "Sales": transactions(1, 2) = 100
    transactions(2, 1) = "Fees": transactions(2, 2) = 12
    rows = a.DimSplit(transactions)
    Debug.Print rows(1)(1), rows(1)(2) ' Expected: Sales, 100
    Debug.Print a.DimCounter(rows)    ' Expected: 1; inner arrays are separate
End Sub

Behavior and edge cases#

The output uses nested indexing, such as rows(rowIndex)(columnIndex), rather than matrix indexing rows(rowIndex, columnIndex).
Both sets of source bounds are preserved in the corresponding outer and inner arrays.
Every row receives a row-array template and then all source elements are copied into it. Row order and value types are preserved.
DimMerge reverses this representation when the inner arrays have compatible bounds. The original matrix is not modified.

Performance#

O(r × c) element work and O(r × c) output storage, plus an O(c) row template and O(r) outer-array descriptors.

View implementation

Function DimSplit(ByVal vArr As Variant) As Variant
    'Converts a two-dimensional array into a one-dimensional array of row arrays

    Dim vArr_Template As Variant
    Dim lRow As Long
    Dim lCol As Long
    Dim vArr_Out As Variant

    If Not IsArray(vArr) Then Exit Function
    If Me.DimCounter(vArr) <> 2 Then Exit Function
    ReDim vArr_Out(LBound(vArr, 1) To UBound(vArr, 1))
    ReDim vArr_Template(LBound(vArr, 2) To UBound(vArr, 2))
    For lRow = LBound(vArr_Out) To UBound(vArr_Out)
        vArr_Out(lRow) = vArr_Template
        For lCol = LBound(vArr, 2) To UBound(vArr, 2)
            vArr_Out(lRow)(lCol) = vArr(lRow, lCol)
        Next lCol
    Next lRow

    If IsArray(vArr_Out) Then
        DimSplit = vArr_Out
    End If
End Function