Solutions for those exercises.

Questions

1. What is the keyword used to call the constructor from the base class?

• this.
• the name of the base class.
• base
• over
• inherits

Problems

1. Consider the diagram representing the “Room”, “ClassRoom”, “Office” classes and their relations.

Suppose you are given an implementation of the Room class, such that

    Room test = new Room("UH", 243);
    Console.WriteLine(test);

displays

UH 243

1. Write an implementation of the ClassRoom class. Your ToString method should display the room’s building and number, in addition to whether it has AV set-up.

2. Write a SameBuilding static method to be placed inside the Room class such that

   Office test1 = new Office("UH", 127, "706 737 1566");
   ClassRoom test2 = new ClassRoom("UH", 243, true);
   Office test3 = new Office("AH", 122, "706 729 2416");
   Console.WriteLine(Room.SameBuilding(test1, test2));
   Console.WriteLine(Room.SameBuilding(test2, test3));

   Would display “true” and “false”.

3. Consider the diagram representing the “Article”, “Book” classes and their relations.

   

   1. Write a (partial) implementation of the Article abstract class:

      1. Write an implementation for the price attribute: you can either use a getter and a setter (as pictured in the UML diagram), or a property. However, in both cases, setting the price to a negative value should result in an ArgumentOutOfRangeException exception being thrown.
      2. Write an abstract ShippingCosts() method.

   2. Now, assume given a complete implementation of the Article abstract class. Write a complete implementation of the Book class (header included), containing:

      1. An implementation of the Title property using auto-properties.
      2. A Book constructor that passes the idP and priceP arguments to the Article constructor. The titleP argument should be assigned to the Title property.
      3. A ShippingCosts() method that returns either 5.0, or 10% of the Book’s price, whichever is smallest.

   3. Write statements that, if placed in a Main method, would

      1. Create a Book with Id “AAA001”, price $12.5, titled “What it’s like to be a bird”.
      2. Display (nicely) its shipping costs.
      3. Display its Id (as retrieved from the object).