How can I get the structure of $form->getData()

I have difficulties to get the structure of the array / object form->getData(). also I wanted to know there is a way to get it easily.

I have tried the following but there are to many information therefore it isn't readable

$data = $form->getData();
$for_twig_data = var_dump($data);

I also tried the following, but $data_value_value is an object, therefore I cannot fetch throught it:

  $liste_key = '';
  foreach($data as $data_key => $data_value)
  {
      $liste_key = $liste_key."[".$data_key."]";
      if(is_array($data[$data_key]))
      {
        foreach($data_value as $data_value_key => $data_value_value)
        {
          $liste_key = $liste_key."(".$data_value_key.")".$data_value_value;
          if(is_array($data[$data_key][$data_value_key]))  
          {
            foreach($data_value_value as $data_value_value_key => $data_value_value_value)
            {
              $liste_key = $liste_key."{".$data_value_value_key."}";
            }
          }
        }
      }
  }