PHPOffice / PhpSpreadsheet

     * @param int $startRow The row number at which to start iterating

     * @param int $endRow Optionally, the row number at which to stop iterating

     */

    public function __construct(Worksheet $subject = null, $columnIndex = 'A', $startRow = 1, $endRow = null)

    {

        // Set subject

        $this->worksheet = $subject;

        $this->columnIndex = Coordinate::columnIndexFromString($columnIndex);

        $this->resetEnd($endRow);

        $this->resetStart($startRow);

    }

    /**

     * (Re)Set the start row and the current row pointer.

     * @param string $startColumn The column address at which to start iterating

     * @param string $endColumn Optionally, the column address at which to stop iterating

     */

    public function __construct(Worksheet $worksheet = null, $rowIndex = 1, $startColumn = 'A', $endColumn = null)

    {

        // Set subject and row index

        $this->worksheet = $worksheet;

        $this->rowIndex = $rowIndex;

        $this->resetEnd($endColumn);

        $this->resetStart($startColumn);

    }

    /**

     * (Re)Set the start column and the current column pointer.