Untitled

<html>
<head>
  <title>test applikation</title>
</head>
<body>
  <h1>Hallo Student</h1>

  <form>
    Matrikel:<br>
    <input type="text" name="matrikel"><br>
    <input type="submit" value="Submit">
  </form>
  <?php

	function durchschnitt(array $notes) {
	  $Anzahl = count($notes);
	  $Summe = 0.0;
	  $i = 0;
	  while ($i < $Anzahl) {
		$Summe = $Summe + $notes[$i];
		$i = $i + 1;
	  }
	  $Durchschnitt = $Summe / $Anzahl;
	  return $Durchschnitt;
	}

    if (is_int((int) $_GET['matrikel'])) {
	$matrikel = $_GET['matrikel'];
	$Noten = array();
	$link = new mysqli('localhost', 'notenapp', 'start123', 'notenapp');
	$result = $link->query("SELECT note.wert as wert, kurs.name as name FROM note, kurs, student WHERE note.kurs_id = kurs.id AND note.student_id = student.id AND student.matrikel = '$matrikel'");
	while ($row = $result->fetch_row()) {
		$note = $row[0];
		$Noten[] = $note;
		$name = $row[1];
		echo "<p>$name: $note</p>";
	}

	/* $Noten = array(1.0, 5.0, 1.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0); */

	echo "<p><strong>" . date('Y-m-d i:s') . "</strong></p>";
	echo "<p><strong>" . durchschnitt($Noten) . "</strong></p>";

	if (count($Noten) == 0) {
	  echo "<p><strong>Sie haben keine Noten.<strong></p>";
	} elseif (durchschnitt($Noten) > 4) {
	  echo "<p><strong>Sie haben nicht bestanden! (Sorry :-( )<strong></p>";
	} else {
	  echo "<p><strong>Sie haben bestanden! :-)<strong></p>";
	}
    }
?>

</body>
</html>