Code snippet that can be used to check if user has permission to special node in Drupal 8.
Example check if current user has permission to update the node:
$node = \Drupal\node\Entity\Node::load(NID);
$user = \Drupal\user\Entity\User::load(\Drupal::currentUser()->id());
$check = $node->access('update', $user);
Example check if current user has permission to view the node:
$node = \Drupal\node\Entity\Node::load(NID);
$user = \Drupal\user\Entity\User::load(\Drupal::currentUser()->id());
$check = $node->access('view', $user);
Example check if current user has permission to create the node:
$node = \Drupal\node\Entity\Node::load(NID);
$user = \Drupal\user\Entity\User::load(\Drupal::currentUser()->id());
$check = $node->access('create', $user);
Example check if current user has permission to delete the node:
$node = \Drupal\node\Entity\Node::load(NID);
$user = \Drupal\user\Entity\User::load(\Drupal::currentUser()->id());
$check = $node->access('delete', $user);
