[micscr]

Анализируй:

$x = array('xxx'=> array('ttt' => 3, 'kkk' => 4 ), 'yyy' => 123);
echo '<pre>' . print_r($x, true) . '</pre>';
$s = json_encode($x);
echo $s;
echo '<pre>' . print_r(json_decode($s, true), true) . '</pre>';