Anton B

$arr = ['one' => ['two' => 'kek']];
$key = '[one][two]';

function arr_key_val($arr, $key) {

	$keys = trim($key, '[]');
	$keys = explode('][', $keys);

	$return = $arr;
	foreach ($keys as $k)
		$return = $return[$k];

	return $return;
}

echo arr_key_val($arr, $key);

header("HTTP/1.1 403 Forbidden");
header("Location: http://" . $_SERVER['HTTP_HOST'], TRUE, 403);
exit();

<form method="post" id="color_send">
<label><input type="radio" name="color" value="1" /> красный</label>
<label><input type="radio" name="color" value="2" /> черный</label>
<input type="submit" name="send" value="Отправить" />
</form>

<script>
$(function () {
    $('#color_send').submit(function () {
        $.post('/send.php', $(this).serialize());
        return false;
    });
});
</script>

$text_arr = []; // массив тестов
$word = 'слово'; // искомое слово

usort($text_arr, function ($a, $b) use ($word) {    
    return substr_count($a, $word) >= substr_count($b, $word) ? -1 : 1;
});