我可以在php创建的一个表中使用多个非嵌套的foreach吗？

Question

I created a table using PHP with two nested foreachs and it worked. Later I wanted the table header to be in separate array and added non-nested foreach above the first one. But that doesn't work for some reason which I can't figure out. Thank you in advance.

<?php
  $hlavicka = array ("Tank", "Kanón", "Sekundární výzbroj", "Pancéřování");

  $tanky = array (
    "M4 Sherman" => array ("76 mm", "2krát 7,62 mm", "max. 106 mm"),
    "Panzer IV" => array ("75 mm", "2krát 7,62 mm", "max. 80 mm"),
    "M26 Pershing" => array ("90 mm", "2krát 7,62 mm, 1krát 12,7 mm", "max. 114 mm"),
    "Centurion" => array ("84 mm", "1krát 7,62 mm", "max. 154 mm"),
    "IS-2" => array ("122 mm", "3krát 7,62 mm, 1krát 12,7 mm", "max. 160 mm"),
  );

  function tabulka($hlavicka, $tanky) {
    $vysledek = "<table>";

    $vysledek .= "<tr>";
    foreach ($hlavicka as $nadpisy) {
      $vysledek .= "<th>";
      $vysledek .= $nadpisy;
      $vysledek .= "</th>";
    }
    $vysledek .= "</tr>";

    foreach ($tanky as $stroje => $parametry) {
      $vysledek .= "<tr>";
      $vysledek .= "<td>";
      $vysledek .= $stroje;
      $vysledek .= "</td>";
      foreach ($parametry as $vsechno) {
        $vysledek .= "<td>";
        $vysledek .= $vsechno;
        $vysledek .= "</td>";  
      }
      $vysledek .= "</tr>";
    }

    $vysledek .= "</table>";
    return $vysledek; 
  }
  echo tabulka($tanky);
?>