如何在echo函数中获取同名多选菜单的值

<form method="post" action="process_form.php">
  <select name="my_menu[]" multiple>
    <option value="option1">Option 1</option>
    <option value="option2">Option 2</option>
    <option value="option3">Option 3</option>
  </select>
  <input type="submit" value="Submit">
</form>

<?php
if(isset($_POST['my_menu'])){
  $selectedOptions = $_POST['my_menu'];
  foreach($selectedOptions as $option){
    echo $option . "<br>";
  }
}
?>