ReDim v(UBound(b) - (UBound(b) < 0), 1)

Arrays in VBA can have a 'Base' of 0 or 1. The base is simply the default first element of an array. For example you would not want an array starting at 0 if you were stepping through an array and storing row data using the array element number, there is no Row 0.

The default array base is set using the

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statements at the top of the module. These only affect the module they are declared in.

The code is simply to take account of the Base settings when re-dimming an array. You can see the effects with the following code. Add to a new module, include the Base 0 statement at the top and copy

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Use F8 to step through the code and have the Immediate (Ctrl-G) window open to see the results.

Change the Option Base statement to 1 and step through it again - the results will be different.

(UBound(b) < 0) returns True if the upper bound of b is < 0, else False.

When a Boolean is part of an arithmetic operation, True is coerced to -1 and False to 0.

So ReDim v (UBound(b) − (UBound(b) < 0) , ...) sizes the first dimension of v to be either the same as UBound(b) if UBound(b) >=0, or one greater if the UBound(b) is < 0.

The rationale for doing so doesn't appear in the code.

how the upper bound of a table can be <0?

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