Download or clone the C# project Library.
This exercise is about using and modifying an existing class. The solution contains a new class called Book, in the file Book.cs.
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Have a look inside the Book.cs file, and see what the Book class definition contains. It is a fairly simple class, with some instance fields, one constructor and some Get… methods. The methods BorrowFromLibrary and ReturnToLibrary are noteworthy; they are to be used when a user loans a book from the library, and returns it again. Also, the method PrintInformation prints out all information about a book.
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Now try to use the Book class yourself. Insert some code into the solution (in the usual place for inserting code), that does the following:
a. Creates a new Book object
b. Print out some information about the book (there is a method you can call for that, remember?)
c. Loan the book, and print the book information again
d. Return the book, and print the book information again
- After this, we decide that we want to keep track of the number of times a book has been borrowed. To do this, you must add code to the Book class. More specifically, you need to:
a. Add a new instance field numberOf Loans to store the number of times a book has been borrowed (what would be a good type to use for this field?)
b. Update the constructor to give this instance field an initial value (what seems like an obvious initial value?)
c. Figure out when we should change the value of the new field (Hint: What method will be activated when you borrow a book?)
d. Add a method GetNumberOfLoans, that will return the value of the new field
e. Update the code that prints book information, so that it also includes the number of times the book has been loaned
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Finally, test your new code by updating the code from part 2. You should try to loan and return a book several times, to see if the value for number of book loans is updated correctly
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[Extra – only if you have time] It seems strange that we can call BorrowFromLibrary many times, without calling ReturnToLibrary in between those calls. That does not make sense in the real world. Could we somehow change the code to handle this (Hint: That would probably require use of a conditional statement, which we have not really talked about yet…)?