遍历 foreach

<?php
   /*$c=array(a,b,c,d,f);
     foreach ($c as $id=>$v){
     echo $v."<br>";
     }
     echo "<br>";*/
    $d=array(array(1,2,3,4),array(d,e,t,t),array(dfe,ew,t,e));
    foreach ($d as $id=>$v){
    if (is_array($v)){
      foreach ($v as $vv){
      echo $vv."<br>";
      }
    }
    else echo $v."<br>";
    }