Exercise 5A

Implement a class Bookstore for representing bookstores having books in two languages: Italian and German. Each Bookstore object should maintain the following information:

• the number of books in Italian language;
• the number of books in German language.

The Bookstore class should export to its clients the following methods:

• A constructor to create a Bookstore object with a given initial number of books. The constructor has two parameters: one indicates the initial number of books in Italian language, another the initial number of books in German language.
• addBookI, which takes one parameter of type int and increases the number of books in Italian language by its value.
• addBookG, which takes one parameter of type int and increases the number of books in German language by its value.
• getOverallBooksNumber, which returns the total number of books (both in Italian and German language) stored in a bookstore.
• getPercentageOfBooksI, which returns the percentage of books in Italian language. The required percentage is a real number (i.e., float) and is equal to:
  
  
  100.0 * number_of_books_in_italian_language / overall_number_of_books
  
  The method should work correctly also in the case where the overall number of books is 0, and in this case it should return 0 as percentage.
• getPercentageOfBooksG, which returns the percentage of books in German language. The required percentage is a real number (i.e., float) and is equal to:
  
  
  100.0 * number_of_books_in_german_language / overall_number_of_books
  
  The method should work correctly also in the case where the overall number of books is 0, and in this case it should return 0 as percentage.

Finally, implement a client class which:

• Reads from the keyboard the initial number of books in Italian language, and the number of books in German language
• Creates a Bookstore object with a given initial number of books.
• Reads from the keyboard an additional number of books in Italian language and updates the object with its value.
• Reads from the keyboard an additional number of books in German language and updates the object with its value.
• Prints the percentage of books in Italian language.
• Prints the percentage of books in German language.
• Depending on the percentage of books in each language, prints one of the messages:
  • "The majority of books is in Italian"
  • "The majority of books is in German"
  • "The numbers of books in Italian and German are equal"

Solution

Exercise 5B

Plan and implement a class Car with the following properties:

• licensePlate is a string holding the car's license number;
• mileage is an integer holding the car's total covered distance in km;
• acquisitionYear is an integer holding the year the car was first bought;
• basePrice is a double holding the car's base price when it was first bought;
• owner is the current car's owner.

The class Car should define the following methods:

• the constructor: it takes the license number, the acquisition year and the base price as parameters and sets mileage to 0 and owner to null;
• so called "getters": i.e. methods for all attributes that return the field's value;
• a method addToMileage that increments mileage by an integer value, passed as parameter;
• a method setOwner that sets the owner field to a string value, passed as parameter.

Furthermore, design and implement a client class with a static method getCurrentValue that computes the car's current value, given a car object and the current year. Use the equation:

Solution