PHP multidimensional array key collapse -

i'd collapse multidimensional array that

$arr = array(     'first' => array(         'second' => array(             0 => 'foo',             1 => 'bar'         )     ) ); 

would collapse to

$arr = array(     'first[second][0]' => 'foo',     'first[second][1]' => 'bar' ); 

what i'm trying restore multipart/form-data $_post array original request body, this:

------webkitformboundaryxioccklmg4al6vbh content-disposition: form-data; name="first[second][0]"  foo ------webkitformboundaryxioccklmg4al6vbh content-disposition: form-data; name="first[second][1]"  bar ------webkitformboundaryxioccklmg4al6vbh-- 

try code:

$arr = array(     'first' => array(         'second' => array(             0 => 'foo',             1 => 'bar'         )     ) ); $result = array(); function processlevel(&$result, $source, $previous_key = null) {     foreach ($source $k => $value) {         $key = $previous_key ? "{$previous_key}[{$k}]" : $k;         if (!is_array($value)) {             $result[$key] = $value;         } else {             processlevel($result, $value, $key);         }     } } processlevel($result, $arr); var_dump($result); die(); 

it outputs:

array(2) {   ["first[second][0]"] => string(3) "foo"   ["first[second][1]"] => string(3) "bar"  }