Two meanings return in NewSheet(name string) int

[Charnnarong]

I would like to thank to all contributors for creating such a great library. It is tremendous help in my work. I have a minor issue here.

https://github.com/360EntSecGroup-Skylar/excelize/blob/520aa679f34bafbc00626151075b0b123eceb516/sheet.go#L36

The comment says Returns the number of sheets in the workbook (file) after appending the new sheet. However, the return number has two meanings.

1. sheet count
2. sheet index

For instance

// f *excelize.File
totolSheet := f.NewSheet("newSheetName")
log.Println("create new sheet: ", totolSheet, f.SheetCount)

output.
totalSheet is always one less than f.SheeetCount if "newSheetName" hasn't existed before (succeed in appending a new sheet).
Both are equal in case of "newSheetName" is already exist.

I faced the problem by reading the comment and wrote my code as
tempIndex := f.NewSheet(tempName) - 1
now, I have to change to
tempIndex := f.NewSheet(tempName)
which isn't quite having the same meaning with the function comment.

[xuri]

Thanks for your feedback, as you say the index returned by NewSheet when the worksheet already exists is wrong, it shouldn't be sheet count, I'll fix it.

[Charnnarong]

Great, thank you for the quick action! Returning the index is more coherence. Just a kind reminder of updating the comment to reflect the change would be very appreciated.

[xuri]

I have fixed it, please try to use the master branch code.

[Charnnarong]

Thank you for the fix. How about the method's comment. The original one is

// NewSheet provides function to create a new sheet by given worksheet name.
// When creating a new spreadsheet file, the default worksheet will be
// created. Returns the number of sheets in the workbook (file) after
// appending the new sheet.

The last sentence Returns the number of sheets in the workbook (file) after appending the new sheet.
Shouldn't it be Returns the index of the sheets in the workbook (file) after it appended ? Or anything similar as you see fit as we are not returning the number of sheets in the workbook anymore.

[xuri]

I have updated the docs of the NewSheet.

[Charnnarong]

Thank you for the fix. The comment is now crystal clear. And also with your additional of the default worksheet named ``Sheet1`` will be created. is left no user with no double what it is going to happen when calling the function. Thank you again.