Merge Two Arrays

Category:

Lists, Collections and Arrays

Type:

Snippets

Difficulty:

Intermediate

Author:

Intelligent Solutions Inc.

Version Compatibility: Visual Basic 6, Visual Basic 5

More information:

Combines two arrays. Refer to comments for usage instructions and example.

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
' (None)

Code:

Public Sub ArrayMerge(SourceArray As Variant, _
  DestArray As Variant, Optional KillSource As Boolean = False)

'MERGES TWO ARRAYS
'SourceArray is appended to end of DestArray
'If KillSource is set to true, then SourceArray 
'is erased following the merge

'EXAMPLE

'Dim i(2) As Integer
'Dim j() As Integer
'Dim iCtr As Integer
'
'ReDim j(2) As Integer
'i(0) = 4
'i(1) = 5
'i(2) = 6
'j(0) = 1
'j(1) = 2
'j(2) = 3
'ArrayMerge i, j
'
'For iCtr = 0 To UBound(j)
' Debug.Print j(iCtr) 'Outputs 1 2 3 4 5 6
'Next
   
Dim l As Long, lngPos As Long, lngTemp As Long
Dim lngUboundSource As Long
Dim lngLBoundSource As Long
Dim lngUboundDest As Long

If (Not IsArray(SourceArray)) Or (Not IsArray(DestArray)) _
  Then Exit Sub

lngLBoundSource = LBound(SourceArray)
lngUboundSource = UBound(SourceArray)
lngUboundDest = UBound(DestArray)
lngTemp = lngUboundSource - lngLBoundSource + 1

lngPos = UBound(DestArray) + 1

ReDim Preserve DestArray(LBound(DestArray) To _
    UBound(DestArray) + lngTemp)

For l = lngUboundDest To lngPos Step -1
   DestArray(l + lngTemp) = DestArray(l)
Next

lngUboundSource = lngPos + lngTemp - 1

For l = lngPos To lngUboundSource
   DestArray(l) = SourceArray(l - lngPos)
Next

If KillSource = True Then Erase SourceArray
End Sub