array_walk_recursive - modify both keys and values
<p>How can you modify both keys and values with <code>array_walk_recursive</code>??</p>

<p>Here only the values are encoded</p>

<pre><code>function _utf8_encode($arr){
    array_walk_recursive($arr, 'utf8_enc');

    return $arr;
}

function utf8_enc(&amp;$value, &amp;$key){
    $value = utf8_encode($value);
    $key = utf8_encode($key);
}
</code></pre>
