如何获得第一个和最后一个元素 <li> ？

Question

I would like to get first and last element in <li> :

<script>
  function editMediaInfo(mediaID){
    var x = document.getElementsByTagName("li")[0]
    alert(x);
  }
</script>

<?php
  $x = 1;
  echo "<ol>";

  while($x <= 5){
    echo "<li id={$x}> item {$x} </li>";
?>
<button onclick="editMediaInfo('<?php echo $x; ?>')">Click</button>
<?php
    $x++;
  }

  echo "</ol>";
?>

When I click the button, I'd like to get the first and the last element in <li> . How can I do that?

Answer 1

You can try this way with lastChild property

    var x = document.getElementsByTagName("ul")[0];
    var lastchild = x.lastChild;
    alert(lastchild);