Why is UDF always returning False?

[ChemistB]

I borrowed the function from shg in this thread to test if a sheet exists but it is always returning false.

http://www.excelforum.com/excel-prog...et-exists.html

I am including the entire code. It does a regression analysis on data for a second degree polynomial. In doing so, it creates a worksheet called Regression. So I test first to see if this sheet already exists within the workbook and then ask the user to delete it if it does. I've stepped through the function and the function is always returning False whether Regression exists or not. Thanks in advance.

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[shg]

You should borrow it all

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[ChemistB]

Okay, that works great! I still don't understand why. If it was always giving FALSE before, shouldn't putting a NOT in front of it always give true? How is the code being interpreted? Thanks

[shg]

If the second line errors, as it will if the sheet doesn't exist, then SheetExists is unmodified, and therefore False.

If the line doesn't error, then the the result of the assignment is True (the sheet ain't nothin', and therefore is sumthin').

Capiche?

[Andy Pope]

If the sheet does not exist an error is raised.
So actually no resulting value is assigned to SheetExists. It defaults to False.

[ChemistB]

Capiche! Thanks to both of you.