ONT4101 Practical 1 Due Date 11 February 2020 at 23:55

4. a. Create an application named BookDemo that declares and demonstrates objects of the Book class and its descendents. The Book class includes auto- implemented properties for the International Standard Book Number (ISBN), title, author, and price. (An ISBN is a unique number assigned to each published book.) Create a child class named TextBook that includes a grade level and a CoffeeTableBook child class that contains no additional fields or properties. In the child classes, override the accessor that sets a Books price so that TextBooks must be priced between $20.00 and $80.00, inclusive, and CoffeeTableBooks must be priced between $35.00 and $100.00, inclusive. Be sure to use valid and invalid values when testing the child class properties.

b. In the Book class you created in Exercise 4a, overload the Object class Equals() method to consider two Books equal if they have the same ISBN. Create a program that declares three Books; two should have the same ISBN and one should have a different one. Demonstrate that the Equals() method works correctly to compare the Books. Save the program as BookDemo2.

c. Write an application that declares two Book objects and uses an extension method named DisplayTitleAndAuthor() with each. The method displays a Books title, the word by, and the authors name. Save the program as BookDemo3.

5. a. Create an application named CustomerDemo that prompts a user for data for five Customer objects, sorts them in ID number order, and displays all their data as well as a grand total of the amounts owed by all customers. The Customer class includes auto-implemented properties for a customer ID number, name, and balance due. Override the ToString() method to return all the details for a customer.

b. Using the Customer class as a base, derive a CreditCustomer class. A CreditCustomer contains all the data of a Customer, plus a field to hold a monthly interest rate. Create a program named CustomerDemo2 that contains an array of five CreditCustomer objects. Prompt the user for all the necessary data. Override the parent class ToString() method to include the child classs additional data. Sort all the records in ID number order and display them with a total amount owed from all CreditCustomers.

c. Write an application named CustomerDemo3 that uses an extension method for the CreditCustomer class. The method computes and returns a CreditCustomers monthly payment due (1/24 of the balance). The application should allow the user to enter data for five CreditCustomers and then display all the data for each.

7. Create an application named RecoveringDemo that declares objects of three types: Patient, Upholsterer, and FootballPlayer. Create an interface named IRecoverable that contains a single method named Recover(). Create the classes named Patient, Upholsterer, and FootballPlayer so that each implements IRecoverable. Create each classs Recover() method to display an appropriate message. For example, the Patients Recover() method might display I am getting better"

hi its C# .NET and not javascript