Creating a field that will give an array when submitted

Form element

  <input type="checkbox" name="PersonsSelected[]" value="$PersonUserId" />

Form handler

  $SelectedPersons = array();
  if (isset($_POST['PersonsSelected']))
  {
    $SelectedPersons = $_POST['PersonsSelected'];
        
    foreach ($SelectedPersons as $SelectedPerson)
    {
      // = $SelectedPerson
    }

  }