public void schrijfQuizzenNaarBestand(QuizCatalogus quizCatalogus) {
		File file = new File("bestanden/quizzen");
		try {
			PrintWriter writer = new PrintWriter(file);
			for (int i = 0; i < quizCatalogus.getQuizzen().size(); i++) {
				Quiz quiz = quizCatalogus.getQuizzen().get(i);
				String lijn = quiz.getId() + "," + quiz.getAantalDeelnames()
						+ "," + quiz.getLeerjaar() + ","
						+ quiz.getLeraar().getVoorNaam()+"," +quiz.getLeraar().getFamilieNaam()+ ","
						+ quiz.getOnderwerp() + ","
						+ quiz.getQuizStatus();
				for (Opdracht opdr :quiz.getOpdrachten()){
					lijn+=","+opdr.getId();
				}
				writer.println(lijn);
			}
			if (writer != null)
				writer.close();
		} catch (Exception ex) {
			System.out.println(ex.getMessage());
		}
	}