// Import \Drupal\Component\Utility\SortArray class
use Drupal\Component\Utility\SortArray;
// Then applied it manually
uasort($result, function($a, $b) {
return SortArray::sortByKeyString($a, $b, 'ARRAY_KEY_TO_SORT');
});
// Also It's possible to use without a closure function
uasort($form['elements'], [
'\Drupal\Component\Utility\SortArray',
'sortByWeightProperty'
]);