Ok。いくつかのことを明確にしましょう。
したがって、列Aには10,000ランダムに生成された値があり、列Iには5000ランダムに生成された値があります。このように見えます
10,000 個のセルに対して 3 つの異なるコードを実行しました。
アプローチ、for i = 1 to ... for j = 1 to ...あなたが提案しているもの
Sub ForLoop()
Application.ScreenUpdating = False
Dim stNow As Date
stNow = Now
Dim lastA As Long
lastA = Range("A" & Rows.Count).End(xlUp).Row
Dim lastB As Long
lastB = Range("I" & Rows.Count).End(xlUp).Row
Dim match As Boolean
Dim i As Long, j As Long
Dim r1 As Range, r2 As Range
For i = 2 To lastA
Set r1 = Range("A" & i)
match = False
For j = 3 To lastB
Set r2 = Range("I" & j)
If r1 = r2 Then
match = True
End If
Next j
If Not match Then
Range("I" & Range("I" & Rows.Count).End(xlUp).Row + 1) = r1
End If
Next i
Debug.Print DateDiff("s", stNow, Now)
Application.ScreenUpdating = True
End Sub
シドのアプローチ
Sub Sample()
Dim wsDes As Worksheet, wsSrc As Worksheet
Dim rngDes As Range, rngSrc As Range
Dim DesLRow As Long, SrcLRow As Long
Dim i As Long, j As Long, n As Long
Dim DesArray, SrcArray, TempAr() As String
Dim boolFound As Boolean
Set wsDes = ThisWorkbook.Sheets("Sheet1")
Set wsSrc = ThisWorkbook.Sheets("Sheet2")
DesLRow = wsDes.Cells(Rows.Count, 1).End(xlUp).Row
SrcLRow = wsSrc.Cells(Rows.Count, 1).End(xlUp).Row
Set rngDes = wsDes.Range("A2:A" & DesLRow)
Set rngSrc = wsSrc.Range("I3:I" & SrcLRow)
DesArray = rngDes.Value
SrcArray = rngSrc.Value
For i = LBound(SrcArray) To UBound(SrcArray)
For j = LBound(DesArray) To UBound(DesArray)
If SrcArray(i, 1) = DesArray(j, 1) Then
boolFound = True
Exit For
End If
Next j
If boolFound = False Then
ReDim Preserve TempAr(n)
TempAr(n) = SrcArray(i, 1)
n = n + 1
Else
boolFound = False
End If
Next i
wsDes.Cells(DesLRow + 1, 1).Resize(UBound(TempAr) + 1, 1).Value = _
Application.Transpose(TempAr)
End Sub
私の（方法）アプローチ
Sub Main()
Application.ScreenUpdating = False
Dim stNow As Date
stNow = Now
Dim arr As Variant
arr = Range("A3:A" & Range("A" & Rows.Count).End(xlUp).Row).Value
Dim varr As Variant
varr = Range("I3:I" & Range("I" & Rows.Count).End(xlUp).Row).Value
Dim x, y, match As Boolean
For Each x In arr
match = False
For Each y In varr
If x = y Then match = True
Next y
If Not match Then
Range("I" & Range("I" & Rows.Count).End(xlUp).Row + 1) = x
End If
Next
Debug.Print DateDiff("s", stNow, Now)
Application.ScreenUpdating = True
End Sub
結果は次のとおりです
ここで、高速比較方法を選択します:)
ランダム値の入力
Sub FillRandom()
Cells.ClearContents
Range("A1") = "Column A"
Range("I2") = "Column I"
Dim i As Long
For i = 2 To 10002
Range("A" & i) = Int((10002 - 2 + 1) * Rnd + 2)
If i < 5000 Then
Range("I" & Range("I" & Rows.Count).End(xlUp).Row + 1) = _
Int((10002 - 2 + 1) * Rnd + 2)
End If
Next i
End Sub