Handling exceptions and Stack Overflow

[computerbear]

Hello,

Code below has requirements commented in. I don't get any errors, but when I go to run it, I immediately get a stack overflow and program closes. I don't even know where to begin to look. I am too new at this. Without a road map to errors, I am lost Thanks.

namespace Assignment_7a_Exception
{
    public class Assignment_7a_Exception
    {
        public static void Main()
        {   
            int x = 0;
        /* In Main create 4 Book objects and use the constructor for Book to pass the four inputs when each object
          * is instantiated, some where the ratio is correct and some where the ratio is not correct. */
            for (x=0; x < 4; ++x)
            {
                Book mybook = new Book();
                Console.WriteLine("Please enter book title: ");
                mybook.Title = Console.ReadLine();
                Console.WriteLine("Please enter name of the author: ");
                mybook.Author = Console.ReadLine();
                Console.WriteLine("Please enter the price of the book: ");
                mybook.Price = Convert.ToDouble(Console.ReadLine());
                Console.WriteLine("Please enter the number of pages in the book: ");
                mybook.NumPages = Convert.ToInt32(Console.ReadLine());
                
            
                try
                {
                    mybook.checkRatio();  
                } // End

                // Catch any thrown exceptions and display BookException Message.
                catch(BookException e)
                {
                    Console.WriteLine(e.Message);
                    Console.WriteLine(e.StackTrace);
                }

            }  // End for
                     
        } //  End main
    } //  End Assignment class
    
    /* Create a Book class that has the following fields:
     *   string title, string author, double price and int number of pages. */
    public class Book
    {
        // Create properties (accessors) for each field.
        private string title;
        public string Title
        {
            get
            {
                return title;
            }
            set
            {
                title = value;
            }
        }

        private string author;
        public string Author
        {
            get
            {
                return author;
            }
            set
            {
                author = value;
            }
        }

        private double price;
        public double Price
        {
            get
            {
                return price;
            }
            set
            {
                price = value;
            }
        }

        private int numPages;
        public int NumPages
        {
            get
            {
                return numPages;
            }
            set
            {
                numPages = value;
            }
        }
        public bool validRatio { get; set; }

        public Book()
                : this("zzz", "zzz", 0.0, 9)
        {
        }

        public Book(string Title, string Author, double Price, int NumPages)
        {
        }

        Book mybook = new Book();
        public void checkRatio()
        {
            const double RATE = .10;
           
            
            // The price-to-pages ratio is determined by checking the following:  price > RATE * pages where RATE = 0.10
            if (Price > (RATE * NumPages))
            {
                mybook.validRatio = true;
            }
            // Throw a BookException if a book object is created that has a price that is more than 10 cents per page
            else
            {
                mybook.validRatio = false;
                BookException be = new BookException();
                /* Create an error message that is passed to the Exception class constructor for the Message property 
                * when a book does not meet the price-to-pages ratio. */
                Console.WriteLine("Ratio for {0} is invalid. Price is {1} for {2} pages.", Title, Price, NumPages);
                throw(be);
            }
        }

    }  //End Book Class
 
    /*Create a BookException class with a constructor that requires three (3) arguments for each book: 
       * a string title, a double price, and an int number of pages. */
    public class BookException : Exception
    {
        public BookException(string Title, double Price, double NumPages)
            : base ()
        {
        }
        public BookException()
        {
        }
    }  //End BookException Class

        // Internal Documentation.

[pitic]

[B]Book mybook = new Book();[/B]
        public void checkRatio()
        {
            const double RATE = .10;
           
            
            // The price-to-pages ratio is determined by checking the following:  price > RATE * pages where RATE = 0.10
            if (Price > (RATE * NumPages))
            {
                [B]mybook[/B].validRatio = true;
            }
            // Throw a BookException if a book object is created that has a price that is more than 10 cents per page
            else
            {
                [B]mybook[/B].validRatio = false;
                BookException be = new BookException();
                /* Create an error message that is passed to the Exception class constructor for the Message property 
                * when a book does not meet the price-to-pages ratio. */
                Console.WriteLine("Ratio for {0} is invalid. Price is {1} for {2} pages.", Title, Price, NumPages);
                throw(be);
            }
        }

    }  //End Book Class

you are creating an instance of class book inside the class declaration. remove the line in bold, and inside the checkRatio() method just use the cariable names (without the preceding object)... c# is clever enough to use the object you created in main.

[skatamatic]

Heres a somewhat cleaner way of making properties, too:

Instead of:

private int numPages;        
public int NumPages        
{            
get            
{                return numPages;            }
set
{                numPages = value;            } 
}

Do this:

public int NumPages { get; set; }

You can even make the get or the set private/protected if need be, depending on the situation.

[computerbear]

Thank you all so much. I appreciate your help.

T