VBScript Array Push

[Travis G]

  Function Push(ByRef mArray, ByVal mValue)
    Dim mValEl

    If IsArray(mArray) Then
      If IsArray(mValue) Then
        For Each mValEl In mValue
          Redim Preserve mArray(UBound(mArray) + 1)
          mArray(UBound(mArray)) = mValEl
        Next
      Else
        Redim Preserve mArray(UBound(mArray) + 1)
        mArray(UBound(mArray)) = mValue
      End If
    Else
      If IsArray(mValue) Then
        mArray = mValue
      Else
        mArray = Array(mValue)
      End If
    End If
    Push = UBound(mArray)
  End Function

It is something I cooked up for my ASP application. I got sick of working around not having a push. It will push a single value onto an array, or push an array of values. I haven't hardened it, yet, but let me know what you think.

[alex_read]

Function Push(ByRef mArray, ByVal mValue)
    Dim intCounter
    Dim intElementCount
 
    If IsArray(mArray) Then
      If IsArray(mValue) Then
        ' Set ubound value once only
        intElementCount = CInt(UBound(mArray))
        ReDim Preserve mArray(CInt(intElementCount + UBound(mValue)))
        
        ' Using for...next is more efficient & quicker than for..each
        For intCounter = 0 To UBound(mValue)
          mArray(intElementCount + intCounter) = mArray(intCounter)
        Next intCounter
      Else
        ReDim Preserve mArray(UBound(mArray) + 1)
        mArray(UBound(mArray)) = mValue
      End If
    Else
      If IsArray(mValue) Then
        mArray = mValue
      Else
        mArray = Array(mValue)
      End If
    End If
    Push = UBound(mArray)
  End Function

[hypert]

If you're trying to do this in VBScript (as I am), there's a minor syntax change ("Next" vs. "Next intCounter". But, I also think there's a bug in how the indexes are calculated.

Here's my version:

Function Push(ByRef mArray, ByVal mValue)
  Dim intCounter
  Dim intElementCount
 
  If IsArray(mArray) Then
    If IsArray(mValue) Then
      ' Set ubound value once only
       intElementCount = UBound(mArray)
      ReDim Preserve mArray(intElementCount + UBound(mValue) + 1)
 
      ' Using for...next is more efficient & quicker than for..each
      For intCounter = 0 to UBound(mValue)
        mArray(intElementCount + intCounter + 1) = mArray(intCounter)
      Next
    Else
      ReDim Preserve mArray(UBound(mArray) + 1)
      mArray(UBound(mArray)) = mValue
    End If
  Else
    If IsArray(mValue) Then
      mArray = mValue
    Else
      mArray = Array(mValue)
    End If
  End If
  
  Push = UBound(mArray)
End Function

[Level99]

Since this is #1 ranked result from Google for VBScript array push, I think we need a little more content.

First of all, the only function that actually works properly "out of the box" (VBScript compiles, indexing properly) is the first post by Travis G.

I'm guilty of blindly copying and pasting (don't worry guys I'm citing the authors / URL for my purposes ) and ran into a problem. I really did want to build a multidimensional array with this. I appreciate the extra logic that flattens passed in arrays to maintain one container; however, I'd like to control it. In my usage I just removed that section of the code. A flag would be helpful. This is just a slightly modified version of Travis G's original solution.

Function Push(ByRef mArray, ByVal mValue, blnDoFlatten)
    Dim mValEl

    If IsArray(mArray) Then
        If IsArray(mValue) Then
            If blnDoFlatten Then
                For Each mValEl In mValue
                    Redim Preserve mArray(UBound(mArray) + 1)
                    mArray(UBound(mArray)) = mValEl
                Next                
            Else
                Redim Preserve mArray(UBound(mArray) + 1)
                mArray(UBound(mArray)) = mValue
            End If
        End If

    Else
        If IsArray(mValue) Then
            mArray = mValue
        Else
            mArray = Array(mValue)
        End If
    End If

    Push = UBound(mArray)
End Function