Online PHP editor | output for 6TKJR

<?php class A1 { public function rows() { $a = array(); $a[] = array('parent_id' => 10, 'category_id' => 13, 'name' => 'id13', 'sort_order' => 7); $a[] = array('parent_id' => 8, 'category_id' => 12, 'name' => 'id12', 'sort_order' => 6); $a[] = array('parent_id' => 7, 'category_id' => 11, 'name' => 'id11', 'sort_order' => 5); $a[] = array('parent_id' => 7, 'category_id' => 10, 'name' => 'id10', 'sort_order' => 4); $a[] = array('parent_id' => 0, 'category_id' => 9, 'name' => 'id9', 'sort_order' => 3); $a[] = array('parent_id' => 0, 'category_id' => 8, 'name' => 'id8', 'sort_order' => 2); $a[] = array('parent_id' => 0, 'category_id' => 7, 'name' => 'id7', 'sort_order' => 1); return $a; } } $query = new A1; $categoryArray = array(); foreach($query->rows() as $row) { if(isset($categoryArray[$row['category_id']])) { $categoryArray[$row['parent_id']][$row['category_id']]['name'] = $row['name']; $categoryArray[$row['parent_id']][$row['category_id']]['elements'] = $categoryArray[$row['category_id']]; unset($categoryArray[$row['category_id']]); } else { $categoryArray[$row['parent_id']][$row['category_id']]['name'] = $row['name']; } } //echo "first stage \n"; //print_r($categoryArray); // second stage echo "\n\n"; getCategory($categoryArray[0]); function getCategory($array){ ksort($array); foreach($array as $key => $row){ if(isset($row['elements'])) { echo('<li>'.$row['name'].'<ul>'); getCategory($row['elements']); echo('</ul></li>'); } else { echo('<li>'.$row['name'].'</li>'); } } }