Unik sammensat array

$Courses = array(
  array('Name' => 'fag1', 'CourseId' => 1, 'Selected' => ''),
  array('Name' => 'fag2', 'CourseId' => 2, 'Selected' => ''),
  array('Name' => 'fag3', 'CourseId' => 3, 'Selected' => ''),
  array('Name' => 'fag4', 'CourseId' => 4, 'Selected' => ''),
  array('Name' => 'fag5', 'CourseId' => 5, 'Selected' => ''),
);

$TeacherCourses = array(
  array('CourseId' => 1, 'Selected' => 'Sel'),
  array('CourseId' => 2, 'Selected' => 'Sel'),
  array('CourseId' => 3, 'Selected' => 'Sel'),
);

html_dump($Courses); 
 
foreach ($TeacherCourses as $TeacherCourseItem)
{
  foreach ($Courses as &$CourseItem)
  {
    if ($CourseItem['CourseId'] == $TeacherCourseItem['CourseId'])
    {
      $CourseItem['Selected'] = $TeacherCourseItem['Selected'];
      break;
    }
  }
}

unset($TeacherCourseItem);
unset($CourseItem);

html_dump($Courses); 

function html_dump($var)
{
  echo("<pre>"); 
  var_dump($var); 
  echo("</pre><br />");
}