<?php

    $arr = array(

        array(

            array(

                array(

                    array(

                        ,,

                    )

                )

            ),

            array(

                "test" => array(,,)

            )

        ),

        array(, , )

    );

    function arr_foreach ($arr) {

        static $data;

        if (!is_array ($arr)) {

            return $data;

        }

        foreach ($arr as $key => $val ) {

            if (is_array ($val)) {

                arr_foreach ($val);

            } else {

                $data[]=$val;

            }

        }

        return $data;

    }

    $result = arr_foreach($arr);

    var_dump($result);

    var_dump($arr);