Array
(
[0] => Array
    (
        [keyword] => lucidus
        [color] => #00ff00
    )

[1] => Array
    (
        [keyword] => commoveo
        [color] => #998899
    )

[2] => Array
    (
        [keyword] => dolus
        [color] => #ff0099
    )

)

<?php
function clean_array($array, $filter = 'check_plain') {
  $clean = array();
  foreach ($array as $key => $val) {
    if (is_array($val)) {
      $clean[$filter($key)] = clean_array($val, $filter);
    }
    else {
      $clean[$filter($key)] = $filter($val);
    }
  }
  return $clean;
}
?>

<?php
function cube($n)
{
    return($n * $n * $n);
}

$a = array(1, 2, 3, 4, 5);
$b = array_map("cube", $a);
print_r($b);
?>

<?php
  function myfunction($v)  {
    $os = array("Dog", "Cat");
    if (in_array($v, $os)) {
      return true;
    }
    return false;
  }
  $a=array(0=>"Dog",1=>"Cat",2=>"Horse");
  print_r(array_filter($a,"myfunction"));
?>