Removing Dashes from ISBN Numbers

Ciaran works in a library, and often has to work with long lists of ISBN numbers in Excel. The numbers must contain either 10 or 13 digits, may contain dashes, and may have leading zeros. He uses text format for cells containing ISBNs in order to keep them intact as text strings. For some purposes, the dashes in the ISBNs have to be stripped out (he uses Find and Replace for this) and that's where the trouble starts. 0-241-95011-2 becomes 241950112 (now it's dropped to 9 digits), and worse, 978-0-00-200784-9 becomes 9.78E+12 (scientific notation). Ciaran can't find any way of working around these two issues, no matter what he does with formatting before or after using Find and Replace to get rid of the dashes.

What is happening is that when you edit the cells, Excel is parsing the cell contents as numbers instead of as text. In this case, the best solution is to make sure that your cell contents are preceded with an apostrophe before you do the Find and Replace to get rid of the dashes. If you have a worksheet that contains a lot of ISBN numbers in column A, you can add the apostrophes with a formula such as the following:

= "'" & A1

You can then copy the results of the formulas and then use Paste Special to paste values back into column A. Each value in column A will then include the apostrophe. When you later perform the Find and Replace, the leading zeroes will still be present and you won't get any attempts at scientific notation.

The reason this works is because the apostrophe is an indicator to Excel that the cell contents should be treated as text. The apostrophe isn't displayed in the worksheet, but it is part of the cell contents, as you can tell by looking at the Formula bar.

Another approach is to bypass using Find and Replace to get rid of the dashes. Instead use the SUBSTITUTE function to remove them, in this manner:

=SUBSTITUTE(A1,"-","")

The SUBSTITUTE worksheet function returns a text value, so any leading zeroes are maintained and Excel doesn't try to convert the numbers to use a numeric format.

If you routinely need to remove the dashes from a range of cells containing ISBNs, you might be better served to use a macro to do the operation. The following macro works upon whatever cells you've selected before running it.

Sub RemoveDashes()
    Dim c As Variant, sISBN As String

    For Each c In Selection
        sISBN = Application.Substitute(c, "-", "")
        c.NumberFormat = "@"
        c.Value = "'" & sISBN
    Next
End Sub

Basically the macro does three things: It removes the dashes, it formats the cell as text, and it places the stripped ISBN back in the cell with an apostrophe before it.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (9927) applies to Microsoft Excel 97, 2000, 2002, and 2003. You can find a version of this tip for the ribbon interface of Excel (Excel 2007 and later) here: Removing Dashes from ISBN Numbers.