How to clear image (or file) field data for specific node programmatically?

Question

I need to clear/remove image (or file) field from specific node.
I have before:

I want to get after code execution for the field:

What code should I use to properly clear image (file) field data?

Answer 1

I assume that your field accepts only one file at a time. This is the code you need to use:

// Replace this with the ID of the node you want to update.
$node_id = 123;

/** @var \Drupal\node\NodeInterface $node */
$node = \Drupal\node\Entity\Node::load($node_id);

// Step 1: remove the file. This will actually delete the file from the
// filesystem, so in case you want to keep it just remove the next two
// lines.
/** @var \Drupal\file\FileInterface $file */
$file = $node->get('field_NAME_OF_YOUR_FIELD')->entity;
$file->delete();

// Step 2: remove the field data.
// The 0 in this case is the index of the item you want to remove. It simply
// means the first value in that field needs to be removed.
$node->get('field_NAME_OF_YOUR_FIELD')->removeItem(0);
// We have to save the changes to the node.
$node->save();

Answer 2

Just to offer an alternate solution

$nid = 123;

// Load the node (EDIT:) while checking if it exists
if(!$node = \Drupal::service('entity_type.manager')
  ->getStorage('node')
  ->load($nid)) {
  // No results for the $nid, bail out early
  return;
}

// EDIT: To make sure there's a value on the field
if(!$node->hasField('field_name') || $node->get('field_name')->isEmpty(){
  return;
}

// Grab the file entity and make it temporary.
// Deletion will be handled by cron.
$file = $node->get('field_name')
  ->entity
  ->set('status', 0)
  ->save();

// Unset the value on the file ref field and save
$node->set('field_name', '')
  ->save()

Answer 3

A solution for multiple files (also good for avoiding errors when the field is empty):

$nid = 123;

$node = \Drupal\node\Entity\Node::load($nid);

// Grab the file entities and make them temporary.
// Deletion should be handled by cron.
$items = $node->get('field_NAME_OF_YOUR_FIELD');
foreach ($items as $item) {
  $file = $item->entity;
  $file->set('status', 0);
  $file->save();
}

// Unset the values on the file ref field and save
$node->set('field_NAME_OF_YOUR_FIELD', []);
$node->save();

This code is based on @Mrweiner great answer.