使用数组中的递归函数获取一行中的所有数据

Question

I have an array like this

Array
(
    [0] => Array
        (
            [id] => 1
            [category_name] => One
            [parent_id] => 
            [children_recursive] => Array
                (
                )
        )
    [1] => Array
        (
            [id] => 2
            [category_name] => Two
            [parent_id] =>
            [children_recursive] => Array
                (
                )
        )
    [2] => Array
        (
            [id] => 3
            [category_name] => Three
            [parent_id] => 
            [children_recursive] => Array
                (
                    [0] => Array
                        (
                            [id] => 17
                            [category_name] => Three and one
                            [parent_id] => 3
                            [children_recursive] => Array
                                (
                                )
                        )
                    [1] => Array
                        (
                            [id] => 19
                            [category_name] => Three and two
                            [parent_id] => 3
                            [children_recursive] => Array
                                (
                                    [0] => Array
                                        (
                                            [id] => 21
                                            [category_name] => Three and two and one
                                            [parent_id] => 19
                                            [children_recursive] => Array
                                                (
                                                )
                                        )
                                )
                        )
                    [2] => Array
                        (
                            [id] => 20
                            [category_name] => Three and three
                            [parent_id] => 3
                            [children_recursive] => Array
                                (
                                )
                        )
                )
        )
    [3] => Array
        (
            [id] => 4
            [category_name] => Four
            [parent_id] => 
            [children_recursive] => Array
                (
                    [0] => Array
                        (
                            [id] => 18
                            [category_name] => Four and one
                            [parent_id] => 4
                            [children_recursive] => Array
                                (
                                )
                        )
                )
        )
)

What I want to from this array

One
Two
Three
Three >> Three and one
Three >> Three and two
Three >> Three and two >> Three and two and one
Three >> Three and three
Four
Four >> Four and one

What I have tried

$category = myarray;
renderNode($category);

function renderNode($node) {
        foreach($node as $cat){
            echo $cat['category_name'].'<br >';
            if(!empty($cat[children_recursive'])){
                renderNode($cat[children_recursive']);
            }
        }
    }

And My output is

One
Two
Three
Three and one
Three and two
Three and two and one
Three and three
Four
Four and one

Edit here is the full array list using var_export so you can just copay and paste

array (
  0 => 
  array (
    'id' => 1,
    'category_name' => 'One',
    'parent_id' => NULL,
    'children_recursive' => 
    array (
    ),
  ),
  1 => 
  array (
    'id' => 2,
    'category_name' => 'Two',
    'parent_id' => NULL,
    'children_recursive' => 
    array (
    ),
  ),
  2 => 
  array (
    'id' => 3,
    'category_name' => 'Three',
    'parent_id' => NULL,
    'children_recursive' => 
    array (
      0 => 
      array (
        'id' => 17,
        'category_name' => 'Three and one',
        'parent_id' => 3,
        'children_recursive' => 
        array (
        ),
      ),
      1 => 
      array (
        'id' => 19,
        'category_name' => 'Three and two',
        'parent_id' => 3,
        'children_recursive' => 
        array (
          0 => 
          array (
            'id' => 21,
            'category_name' => 'Three and two and one',
            'parent_id' => 19,
            'children_recursive' => 
            array (
            ),
          ),
        ),
      ),
      2 => 
      array (
        'id' => 20,
        'category_name' => 'Three and three',
        'parent_id' => 3,
        'children_recursive' => 
        array (
        ),
      ),
    ),
  ),
  3 => 
  array (
    'id' => 4,
    'category_name' => 'Four',
    'parent_id' => NULL,
    'children_recursive' => 
    array (
      0 => 
      array (
        'id' => 18,
        'category_name' => 'Four and one',
        'parent_id' => 4,
        'children_recursive' => 
        array (
        ),
      ),
    ),
  ),
)

Answer 1

Something like that:

function getValues($array, $prefix = '')
{
    $values = [];

    foreach ($array as $value) {
        $values[] = $prefix . $value['category_name'];

        if (!empty($value['children_recursive'])) {
            $values = array_merge($values, getValues($value['children_recursive'], $prefix . $value['category_name'] . ' >> '));
        }
    }

    return $values;
}

implode('<br>', getValues($array));