Online PHP editor | output for pgWZ7

<?php $form_validation_rules = array( array('field' => 'email', 'label' => 'E-Mail-Adresse', 'rules' => 'trim|is_unique[bdb_users.email]|valid_email|required|xss_clean'), array('field' => 'first_name', 'label' => 'Vorname', 'rules' => 'trim|required|xss_clean'), array('field' => 'last_name', 'label' => 'Nachname', 'rules' => 'trim|required|xss_clean'), array('field' => 'tel', 'label' => 'Telefon', 'rules' => 'trim|required|xss_clean'), array('field' => 'address', 'label' => 'Adresse', 'rules' => 'trim|required|xss_clean'), array('field' => 'company', 'label' => 'Unternehmen', 'rules' => 'trim|required|xss_clean'), array('field' => 'password', 'label' => 'Passwort', 'rules' => 'trim|required|xss_clean'), array('field' => 'position', 'label' => 'Position', 'rules' => 'trim|xss_clean'), array('field' => 'department', 'label' => 'Abteilung', 'rules' => 'trim|xss_clean'), array('field' => 'credits', 'label' => 'Credits', 'rules' => 'trim|required|xss_clean|integer'), ); $x = array_map(function($element){return $element['field']}, $form_validation_rules); var_dump($x);