isEmpty und toFirst

public boolean isEmpty()
    {
        if (zaehler==0)
            return true;
        else
            return false;
    }
 
    /*
     * Die Methode toFirst() setzt current auf das erste Element. 
     * Wenn die Liste leer ist, soll nichts verändert werden.
     */ 
    public void toFirst()   //
    {
        current = first;
    }

next

public void next() {
        if (!isEmpty()){           
            if (current.getNext() != null){
                current = current.getNext();
            }else{
                current = first;
            }
        }
    }

previous

public void previous() {
        for (int i = 0; i < count; i++){
		current = current.getNext();
        }
}

addFirst

  public void addFirst(ListenElement new ListenElement) {
 
    if (first == null)
    {
        first = newListenElement;
        current = newListenElement;
    }
    else
    {
        newListenElement.next = first;
        first = newListenElement;
    }
    zaehler = zaehler +1;
    }

suchen

 public String suchen (String suche) 
    {
       current = first;
       while(current.next != null)
       {
           if(current.getInhalt()==suche)
                return current.getInhalt();
 
           current = current.getNext();
       }
 
       return suche + " kann nicht gefunden werdern";
 
 
    }