Magento 2: Check customer logged in

You can check user is logged in or not on the website through a user session in Magento 2. This piece of code is working in any file.

$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
$customerSession = $objectManager->get('Magento\Customer\Model\Session');
if($customerSession->isLoggedIn()) {
   echo "Customer logged in";
}else{
    echo "Not customer logged in";
}