Node

On drupal 8 every elements (almost) are an entity, as any entity you can render a node.

For this, You must use hook_entity_delete.

Update a node:

Example 1 : Update title
$node = \Drupal\node\Entity\Node::load($nid);
$node->setTitle('The new Title')
$node->save();

It is same as normal node creation but must be in format "Y-m-d" (YYYY-MM-DD)

Example:

Methode 1 : Example:

$value = $node->get($field)->value;
$target = $node->get($field)->target_id; // For entity ref

Methode 2 Example:

Example:

$node = \Drupal::routeMatch()->getParameter('node');
if ($node) {
  $nid = $node->id();
}

Programmatically create and translate nodes.

Exemples:

$translation = $entity->getTranslation('de');

Here an example for create node programmatically in Drupal 8