Beginning Visual C# Exercises

seblake · September 24th, 2004, 04:12 PM

1. Public, Private and Protected

2. False, although, when resources are critical, calling a destructor is more timely

3. No, static properties, fields and methods may be independent of object instances

4.

Code:

                   |---------------|
                   |  HotDrink     |
                   |---------------|
                   |  Milk         |             |---------------|
                   |  Sugar        |             | <<Interface>> |
                   |---------------|             |    ICup       |
                   |  Drink()      |             |---------------|
                   |  AddMilk()    |             |  Color        |
                   |  AddSugar()   |             |  Volume       |
                   |---------------|             |---------------|
                           ^                     |  Refill()     |
                           |                     |  Wash()       |
                           |                     |---------------|
           |-----------------------------|
           |                             |
           |                             |
   |---------------|           |---------------|
   |  CupOfCoffee  |---() ICup |  CupOfTea     |---() ICup
   |---------------|           |---------------|
   |  BeanType     |           |  LeafType     |
   |---------------|           |---------------|
   |               |           |               |
   |---------------|           |---------------|

5. private void slakeThirst(object beverage)
        {
            // Employ interface polymorphism
            ICup glassWare;
            glassWare = beverage;
            glassWare.AddMilk();
            glassWare.Drink();
            glassWare.Wash();
        }

dldorman · June 20th, 2007, 08:01 PM

I don't think this code works:

I think you need to add an explicit cast to beverage.
So use:

glassware = (Icup) beverage