Drupal 8 has done a great overhaul in terms of entity management. Lets have a look on how can be access and set data for fields in entities.
All entities implement Drupal\Core\Entity\EntityInterface
Access Entity Title:
The Entity API provides wrapper classes you may use to make dealing with the values of an entities properties and fields easier. Wrappers make it easier to get and set the values of fields and properties as well as to programmatically retrieve additional information about these elements and iterate over lists of values in a consistent manner.
This implies that one need not worry about fetching a node property in the format:
$node->field_name['und'][0]['value']
Enough Said , visit the link: http://rajanmayekar.com/blog/programmatically-creating-deleting-modifyin...
One change wrt to deleting Field Collections is as follows:
<?php
$node = node_load($node_id);
$field_collection_item_value = array();
foreach ($node->field_collection_field[LANGUAGE_NONE] as $key => $value) {
$field_collection_item_value[] = $value['value'];
}
entity_delete_multiple('field_collection_item', array($field_collection_item_value));
?>