How to write code in VBA to remove one random value from 10,000 values?

To solve the problem of removing one random value from 10,000 values in Excel using VBA, we can follow a structured approach. The solution involves reading the data into an array, selecting a random index to remove, and then writing the remaining data back to the worksheet.

Approach

Read Data: Extract the 10,000 values from column A (rows 2 to 10001) into an array for easier manipulation.
Generate Random Index: Use WorksheetFunction.RandBetween to select a random index within the bounds of the array.
Remove Value: Loop through the array and write each value back to the worksheet, skipping the element at the randomly generated index.

Solution Code

Sub RemoveRandomValue()
    Dim ws As Worksheet
    Set ws = ThisWorkbook.Sheets(“Sheet1”) ‘ Replace with your sheet name

    Dim lastRow As Long
    lastRow = 10000 ‘ Since there are 10,000 values starting at row 2

    Dim values() As Variant
    values = ws.Range(“A2:A” & lastRow + 1).Value

    Dim randomIndex As Long
    randomIndex = WorksheetFunction.RandBetween(1, UBound(values))

    Dim i As Long
    For i = 1 To UBound(values)
        If i <> randomIndex Then
            ws.Cells(i, “A”).Value = values(i, 1)
        End If
    Next i

    ‘ Optional: Clear the last cell to avoid leftover data
    ws.Cells(lastRow + 1, “A”).ClearContents
End Sub

Sub RemoveRandomValue()

Dim ws As Worksheet

Set ws = ThisWorkbook.Sheets(“Sheet1”) ‘ Replace with your sheet name

Dim lastRow As Long

lastRow = 10000 ‘ Since there are 10,000 values starting at row 2

Dim values() As Variant

values = ws.Range(“A2:A” & lastRow + 1).Value

Dim randomIndex As Long

randomIndex = WorksheetFunction.RandBetween(1, UBound(values))

Dim i As Long

For i = 1 To UBound(values)

If i <> randomIndex Then

ws.Cells(i, “A”).Value = values(i, 1)

End If

Next i

‘ Optional: Clear the last cell to avoid leftover data

ws.Cells(lastRow + 1, “A”).ClearContents

End Sub

Explanation

Reading Data: The code reads all values from column A starting at row 2 into an array named values.
Random Index Selection: randomIndex is generated to determine which value to remove. Using RandBetween(1, UBound(values)) ensures it falls within the valid range.
Writing Back Data: The loop iterates through each element of the array. If the current index does not match randomIndex, the value is written back to the worksheet. This effectively skips writing the value at randomIndex, thus removing it from the list.

This approach efficiently handles the removal process with clear steps, ensuring that one random value is removed without affecting the rest of the data.