使用html和php删除选择器中重复的选项

<form method="post" action="remove_duplicates.php">
  <select name="options[]" multiple>
    <option value="option1">Option 1</option>
    <option value="option2">Option 2</option>
    <option value="option3">Option 3</option>
    <option value="option4">Option 4</option>
    <option value="option5">Option 5</option>
    <option value="option6">Option 6</option>
    <option value="option7">Option 7</option>
    <option value="option8">Option 8</option>
    <option value="option9">Option 9</option>
    <option value="option10">Option 10</option>
  </select>
  <input type="submit" value="Remove Duplicates">
</form>

<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
  $options = $_POST['options'];
  $uniqueOptions = array_unique($options);
  
  echo '<select name="options[]" multiple>';
  foreach ($uniqueOptions as $option) {
    echo '<option value="' . $option . '">' . $option . '</option>';
  }
  echo '</select>';
}
?>