[Drupal 8] Create file/ media_entity programmatically

file_media_entity.php

<?php 
$filesystem = \Drupal::service('file_system');
// Create file entity.
$image = File::create();
$image->setFileUri($destination);
$image->setOwnerId(\Drupal::currentUser()->id());
$image->setMimeType('image/' . pathinfo($destination, PATHINFO_EXTENSION));
$image->setFileName($filesystem->basename($destination));
$image->setPermanent();
$image->save();
// Create media entity with saved file.
$image_media = Media::create([
  'bundle' => 'image',
  'uid' => \Drupal::currentUser()->id(),
  'langcode' => \Drupal::languageManager()->getDefaultLanguage()->getId(),
  'status' => Media::PUBLISHED,
  'field_image' => [
    'target_id' => $image->id(),
    'alt' => t('Placeholder image'),
    'title' => t('Placeholder image'),
  ],
 ]);
$image_media->save();

Hi Chris, thank you for the reply. If I use autocomplete it will difficult for the editor to browse the existing image they required.

Don't you need to set the thumbnail and field_media_image key in the Media entity too ?
For my case, without that, my media entity was associated with a default file.

"thumbnail" => [
     "target_id" => $file->id(),
     "alt" => $file->getFilename(),
],
"field_media_image" => [
    "target_id" => $file->id(),
     "alt" => $file->getFilename(),
],

Thanks a lot, that worked with "thumbnail" 👍