gistfile1.txt

<?php
//phpinfo(); exit;
header('Content-Type: text/html; charset=utf-8');

$a = array(
    array(
        "id" => 1,
        "parent_id" => 0,
        "name" => "Электротовары"
    ),
    array(
        "id" => 2,
        "parent_id" => 1,
        "name" => "Компьтеры"
    ),
    array(
        "id" => 3,
        "parent_id" => 1,
        "name" => "Бытовая техника"
    ),
    array(
        "id" => 4,
        "parent_id" => 2,
        "name" => "Acer XD5732"
    ),
    array(
        "id" => 5,
        "parent_id" => 3,
        "name" => "Холодильник"
    ),
    array(
        "id" => 6,
        "parent_id" => 3,
        "name" => "Микроволновка"
    ),
    array(
        "id" => 7,
        "parent_id" => 0,
        "name" => "Автомобили"
    ),
    array(
        "id" => 8,
        "parent_id" => 7,
        "name" => "Pego 206"
    )
);


function get_child($id, $data,$i){
    $childrens = array();


    foreach($data as $row){

        if($row['parent_id'] == $id){

            echo $row["name"] . "<br>";


            $arr = array(
                "name" => $row["name"],
                "childrens" => get_child($row['id'], $data,$i)
            );

            $childrens[] = $arr;
        }
        elseif($row['parent_id'] >= 0 ){
            echo $i;
            /* можно просто echo "-" */

        }


    }

    return $childrens;

}



get_child(0, $a,"-");

?>