CODE EXAMPLE FOR PHP

yii2 get cookie

// get the cookie collection (yiiwebCookieCollection) from the "request" component
$cookies = Yii::$app->request->cookies;

// get the "language" cookie value. If the cookie does not exist, return "en" as the default value.
$language = $cookies->getValue('language', 'en');

// an alternative way of getting the "language" cookie value
if (($cookie = $cookies->get('language')) !== null) {
    $language = $cookie->value;
}

// you may also use $cookies like an array
if (isset($cookies['language'])) {
    $language = $cookies['language']->value;
}

// check if there is a "language" cookie
if ($cookies->has('language')) ...
if (isset($cookies['language'])) ...