static void Main(string[] args) { StockMonitor stockMonitor = new StockMonitor(); Stock stock = new Stock("BMW", 11.00m); //stockMonitor.SetData(stock); BMWObserver bmw = new BMWObserver("BMW", stockMonitor); VWObserver vw = new VWObserver("VW", stockMonitor); //AudiObserver audi = new AudiObserver(stockMonitor); // Stock data examples List <Stock> stocks = new List <Stock> { new Stock("BMW", 12.00m), new Stock("VW", 8.00m), new Stock("BMW", 12.50m), new Stock("Audi", 10.00m), new Stock("VW", 7.50m), new Stock("BMW", 13.50m), new Stock("BMW", 14.50m), new Stock("Audi", 10.50m), new Stock("Audi", 11.00m), new Stock("VW", 7.00m), }; foreach (var s in stocks) { stockMonitor.SetData(s); } }