Is there a limit on an Excel worksheet s name length

Question

When I try to set a longish worksheet name using ruby and win32ole with the following code:

require "win32ole"
excel = WIN32OLE.new('Excel.Application')
excel.Visible = 1
puts excel.version
workbook = excel.Workbooks.Add
worksheet1 = workbook.Worksheets.Add
worksheet1.Name = "Pseudopseudohypoparathyroidism" #Length 30, fine
worksheet2 = workbook.Worksheets.Add
worksheet2.Name = "Supercalifragilisticexpialidocious" #Length 34, not fine

I get the following:

12.0
-:9:in `method_missing': (in setting property `Name': ) (WIN32OLERuntimeError)
    OLE error code:800A03EC in Microsoft Office Excel
      You typed an invalid name for a sheet or chart. Make sure that:

 The name that you type does not exceed 31 characters.
 The name does not contain any of the following characters:  :  \  /  ?  *  [  or  ]
 You did not leave the name blank.
    HRESULT error code:0x80020009
      Exception occurred.
        from -:9:in `<main>'

Although Excel 2007 is listed as being installed, version 12.0 complains that the worksheet name is too long. I looked at Excel 2007's requirements and limitations as described in this related response, but I was unable to locate any reference of this limit. (Attempting to manually rename a worksheet indicates there might be a limit, but)

Exists a limit, and if so, can it be modified by adjusting Excel's settings, or is it a hard restriction?

Answer 1

The file format would allow worksheet names to be up to 255 characters long, but if the Excel user interface forbids you from going over 31, don't try to. Giving an app files that are within specs but outside the scope of what the testers would have tested typically results in REALLY bizarre behaviour since the app has weird undocumented limits and idiosyncrasies. (My personal favourite example was when the bold toolbar button in Excel 97 was disabled using the Excel 4.0 bytecode for an if() function in a file with an Excel 97-style stringtable.)