Получить значение вложенного объекта stdClass

Question

Я получаю следующее:

(
[0] => stdClass Object
(
[adm_big_picture] =>
[adm_group] =>
[adm_group_message] =>
[adm_large_icon] =>
[adm_small_icon] =>
[adm_sound] =>
[amazon_background_data] =>
[android_accent_color] =>
[android_group] =>
[android_group_message] =>
[android_led_color] =>
[android_sound] =>
[android_visibility] =>
[app_id] => xxx
[big_picture] =>
[buttons] =>
[canceled] =>
[chrome_big_picture] =>
[chrome_icon] =>
[chrome_web_icon] =>
[chrome_web_image] =>
[content_available] =>
[contents] => stdClass Object
(
[en] => English Message
)
[converted] => 0
[data] => stdClass Object
(
[foo] => bar
)
[delayed_option] =>
[delivery_time_of_day] =>
[errored] => 0
[excluded_segments] => Array
(
)
[failed] => 0
[firefox_icon] =>
[headings] => stdClass Object
(
)
[id] => xxx
[include_player_ids] =>
[included_segments] => Array
(
[0] => All
)
[ios_badgeCount] =>
[ios_badgeType] =>
[ios_category] =>
[ios_sound] =>
[isAdm] =>
[isAndroid] =>
[isChrome] =>
[isChromeWeb] => 1
[isFirefox] => 1
[isIos] =>
[isSafari] => 1
[isWP] =>
[isWP_WNS] =>
[large_icon] =>
[priority] =>
[queued_at] => 1492795180
[remaining] => 0
[send_after] => 1492795180
[small_icon] =>
[successful] => 5
[tags] =>
[filters] =>
[template_id] =>
[ttl] =>
[url] =>
[web_buttons] =>
[wp_sound] =>
[wp_wns_sound] =>
)
)

который устанавливается как массив в $ уведомлениях.

Мне удается получить идентификатор поля с помощью следующего:

for ($i = 0; $i < count($notifications); $i++) {
        $notId = $notifications[$i]->id;

        $title = $notifications[$i]->content->en;

        echo '<p>'.$notId.' - '.$title.'</p>';
    }

Я пытаюсь получить содержимое-> ru сейчас, но не управляю. Может кто-нибудь указать мне правильное направление, пожалуйста?