PHP: Loop through multi-dimensional array. wrte to HTML table

PHP

$a=array(
   array("a","b","c","d"),
   array("e","f","g","h"),
   array("i","j","k","l")
);
echo "<table>";
for($x = 0; $x < 3; $x++){
   for($z = 0; $z < 4; $z++){
       echo "<tr>";
       echo "<td>".$x."</td><td>".$a[$x][$z]."</td>";
       echo "</tr>";
   }
}
echo "</table>";