$worksheet
$worksheet : \PhpOffice\PhpSpreadsheet\Worksheet\Worksheet
Worksheet to iterate.
__construct(\PhpOffice\PhpSpreadsheet\Worksheet\Worksheet $worksheet, string $startColumn = 'A', string $endColumn = null)
Create a new column iterator.
\PhpOffice\PhpSpreadsheet\Worksheet\Worksheet | $worksheet | The worksheet to iterate over |
string | $startColumn | The column address at which to start iterating |
string | $endColumn | Optionally, the column address at which to stop iterating |