import java.util.Arrays;

class Emne implements Comparable<Emne> {

    private String emnekode;

    public Emne(String kode) {
        emnekode = kode;
    }

    public String hentEmnekode() {
        return emnekode;
    }

    @Override
    public int compareTo(Emne annet) {
        return emnekode.compareTo(annet.hentEmnekode());
    }

}

class TestEmne{
    public static void main(String[] args) {
        Emne[] emneliste = new Emne[4];
        emneliste[0] = new Emne("MAT1100");
        emneliste[1] = new Emne("STK1000");
        emneliste[2] = new Emne("IN2010");
        emneliste[3] = new Emne("IN1010");

        for (Emne e: emneliste) {
            System.out.println(e.hentEmnekode());
        }
        System.out.println("\nsorterer");
        Arrays.sort(emneliste);
        for (Emne e: emneliste) {
            System.out.println(e.hentEmnekode());
        }

    }
}