php无限级分类程序

<?php

$a = array(
  'AAAAAA'  =>  array(
        'aaaaaa' => array(
                 '111111',
                 '222222',
                 '333333'
        ),
        'bbbbbb'  => array(
                  '111111',
                 '222222',
                 '333333'
        ),
        'cccccc'  => array(
                  '111111',
                  '222222',
                  '333333'
        ),                     
  ),
  'BBBBBB'  =>   array(
        'aaaaaa' => array(
                  '111111',
                  '222222',
                  '333333'
        ),
        'bbbbbb'=> array(
                  '111111',
                  '222222',
                  '333333'
        ),
        'cccccc'=> array(
                  '111111',
                  '222222',
                  '333333'
        ),
  ),
  'CCCCCC'  => array(
        'aaaaaa'=> array(
                  '111111',
                  '222222',
                  '333333'
        ),
        'bbbbbb'=> array(
                  '111111',
                  '222222',
                  '333333'
        ),
        'cccccc'         => array(
                  '111111',
                  '222222',
                  '333333'
        ),
  ),
);

foreach ($a as $k=>$v){
   echo $k."<br>";
  // if(is_array($v)){
       foreach($v as $key=>$val){
          echo "  ".$key."<br>";
  //     }                           
       if(is_array($val)){
          foreach($val as $kkk=>$vall){
             echo "    ".$vall."<br>";
          }
       }
   }
   echo "<br>";
   }
  
  
    /*******mysql查询无限级分类的代码******/
    /***
   $sql = "SELECT a.Title AS big, b.Title AS small
            FROM largeTitle AS a LEFT JOIN smallTitle  AS b ON  a.ID=b.LargeID";
           
    $a = array();
   
    $r = mysql_query($sql);
   
    while( $arr = mysql_fetch_array($r)){
        $a[$arr['big']] = $arr['small'];
    }
    ***/
?>