How to get connected post IDs by current post ID

To get an array of connected posts you can use the translationIds function. That method is the equivalent of mlp_get_linked_elements in MultilingualPress 2:

The first parameter is the source post id, the second is the column “type” in the wp_mlp_relationships table in the database and the third parameter is the source site id .

About the type value, this must be either “post” or “term”, depending on whether the
Translation of a post or translation of a term is to be queried:

$translations = \Inpsyde\MultilingualPress\translationIds(1, 'post', 1);

it will return an array of key value pairs as site id and post id:

array (size=2)

1 => int 1

2 => int 1

You can loop through $translations like this:

if($translations) {

   foreach($translations as $siteId => $postId) {
      echo 'Site ID: ' . $siteId . ' Post ID: ' . $postId . '<br>';
   }
}