JQuery检查DOM中的重复ID

function checkDuplicateIds() {
  var ids = [];
  $('[id]').each(function() {
    var id = $(this).attr('id');
    if (ids[id] === undefined) {
      ids[id] = 1;
    } else {
      ids[id]++;
      console.log('Duplicate ID: ' + id);
    }
  });
}

$doc = new DOMDocument();
$doc->loadHTML($html);
$xpath = new DOMXPath($doc);
$elements = $xpath->query("//*[@id]");
$ids = [];
foreach ($elements as $element) {
  $id = $element->getAttribute("id");
  if (isset($ids[$id])) {
    echo "Duplicate ID: " . $id . "\n";
  } else {
    $ids[$id] = true;
  }
}