On Fri, Feb 11, 2011 at 5:38 AM, mailing lists <listas.cor...@yahoo.es> wrote:
>>> 12 $sheet -> {MaxRow} ||= $sheet -> {MinRow};
>>
>>Line 12 can be written as:
>>$sheet->{'MaxRow'} = $sheet->{'MaxRow'} || $sheet->{'MinRow'};
>
>
> then that I don't understand is the program logic :-(
>
> what's the purpose of lines 12 and 14??
$sheet->{'MaxRow'} and $sheet->{'MinRow'} are used in the range in
line 13. Line 13 goes through a loop for every $row from MinRow to
MaxRow. If MaxRow isn't defined, the range operator in line 13 will
warn about uninitialized values. And if MaxRow isn't true
Spreadsheet::XLSX will probably complain since there is no row 0 in
Excel.
So line 12 checks to make sure that MaxRow is true. If MaxRow is true,
the ||= operator does nothing, but if MaxRow is false, the ||=
operator assigns the value of MinRow to it. This ensures that MaxRow
is always true (unless MinRow is also undef, which would be a bigger
problem) and that line 13 functions as expected. If MinRow == MaxRow
(i.e. there is only one row), the loop only executes once.
HTH,
-- j
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