This may seem too easy, but I am so desperate.
What I need to do is get the last value of the column "D" which has a
big amount of number, ex. 987654321, the code is fine if the value is only two-digit. I just can't identify the problem.
Dim lastRow As Long
lastRow = Cells(Rows.Count, "D").End(xlUp).Value
Sheets("Sheet1").TxtBox1.Value = lastRow
Like I mentioned in my comment, for such large number you have to declare it as a double.
Dim lastRow As Double
Alternatively since you want to store it in a textbox you can do 2 things
Store it directly in the Textbox.
Option Explicit
Sub Sample1()
Dim lastRow As String
With Sheets("Sheet1")
lastRow = .Cells(.Rows.Count, "D").End(xlUp).Value
.TextBox1.Value = lastRow
End With
End Sub
Sub Sample2()
With Sheets("Sheet1")
.TextBox1.Value = .Cells(.Rows.Count, "D").End(xlUp).Value
End With
End Sub
Long can only handle values up to 2.1B! For any larger values, better use Double instead of Long
3000000000declarelastRowasDouble