array.php

<?php
//old
$this->breadcrumbs[] = array(
    'name' => $translator->trans('Home'),
    'path' => $this->generateUrl('_index', array()),
);
//new
$this->breadcrumbs[] = [
    'name' => $translator->trans('Home'),
    'path' => $this->generateUrl('_index', []),
];