Question

In my VBA program, I have a big array of data, where I need to constantly use its sub-arrays.

My method is:

Redim subArr(rowBegin to rowEnd)
For r = rowBegin to rowEnd
    subArr(r) = bigArr(r)
Next r

Is there any more efficient way to reference this kind of sub-arrays please? Thanks…

Answer 1

Working with arrays is incredibly fast so this will probably give no discernable benefit – althouh I can understand how it may appeal from a coding sense than looping to fill a smaller array

Given you are working with a single element array you could:

1. Introduce a “marker” string inside the large array
2. Join the large array with a delimiter into a single string
3. Split the large array by the “marker” string, then separate the reduced string into a smaller array with the delimiter

The code below dumps the numbers 1 to 100 into an array, and then splits it as above to pull out the first 10 records

Sub test()
Dim bigArr
Dim subArr
Dim strSep As String
Dim strDelim As String
Dim strNew As String
Dim rowBegin As Long
Dim rowEnd As Long

strDelim = ","
strSep = "||"
'fill array with 1 to 100
bigArr = Application.Transpose(Application.Evaluate("row(1:100)"))

rowBegin = 1
rowEnd = 10

bigArr(rowEnd + 1) = strSep
'make a single string
strNew = Join(bigArr, strDelim)
'split the string at the marker 
vArr = Split(strNew, strSep)
ReDim subArr(rowBegin To rowEnd)
'split the smaller string with the desired records
subArr = Split(Left$(vArr(0), Len(vArr(0)) - 1), strDelim)

End Sub