Online PHP editor | output for BUQf5

<?php class SudokuSolver { protected $sudokuColumns; public function __construct (array $sudoku) { $this->sudoku = $sudoku; } // could be static as well public function printOut ($sudoku) { foreach ($sudoku as $column) { foreach ($column as $cell) { echo "|"; if (null !== $cell) { echo $cell; } else { echo " "; } } echo "|\n"; } } public function solve() { $this->checkConsistenz(); } protected function checkConsistenz () { $columns = $this->sudoku; // check rows -> own method $rows = array(); foreach ($columns as $columnIndex => $column) { foreach ($column as $rowIndex => $cell) { $rows[$rowIndex][$columnIndex] = $cell; } //$this->printOut($rows); } foreach ($rows as $row) { $this->checkRow($rowIndex); } } protected function checkRow ($rowIndex) { echo "checking $rowIndex..\n" } } $sudoku = array(); $sudoku[] = array(null,3,null, null,null,null, null,null,null); $sudoku[] = array(null,null,null, 1,9,5, null,null,null); $sudoku[] = array(null,null,8, null,null,null, null,6,null); $sudoku[] = array(8,null,null, null,6,null, null,null,null); $sudoku[] = array(4,null,null, 8,null,null, null,null,1); $sudoku[] = array(null,null,null ,null,2,null, null,null,null); $sudoku[] = array(null,6,null, null,null,null, 2,8,null); $sudoku[] = array(null,null,null, 4,1,9, null,null,5); $sudoku[] = array(null,null,null, null,null,null, null,7,null); $sudokuSolver = new SudokuSolver($sudoku); $sudokuSolver->printOut($sudoku); $sudokuSolver->solve($sudoku);