Minor issue. Index vs Number meanings

[ostropik]

OpenXLSX/OpenXLSX/sources/XLWorkbook.cpp

Line 114 in d928017

if (index < 1 || index > sheetCount()) throw XLInputError("Sheet index is out of bounds");

I understand that for legacy support you won't be able to change this. But maybe small comments/notes will be added.

Bellow confuses me, why I can't use index 0)
doc.workbook().worksheet(0);

[aral-matrix]

I added some comments in cb6a475 - there was a previous @note The index must be 1-based (rather than 0-based) as this is the default for Excel spreadsheets. in the XLSheet sheet(uint16_t index) method, but I agree a few more comments do not hurt.

Tip: Access worksheets by their name if you know it - internally, the index is converted to a name anyways.

The 1-based index is an arbitrary design choice, which @troldal had done consistently for the API. It is logical considering that row and column numbers are 1-indexed (no office application shows a row "0", and column "A" corresponds to index 1 accordingly).

It is my fault for implementing some newer functionality (XLStyles mostly) where I abandoned this 1-based index in favor of a zero-based index, but I did that because in order to implement a lot of functionality within my available time, I gave the users a relatively direct interface to the underlying XML - which e.g. refers to styles by index - and the index that is stored in XML is the zero-based index of a style element within its parent XML node (an array). The same is true for shared string indexes, but it doesn't matter as much there because the user can assign strings to cells without bothering with direct access to XLSharedStrings.