Thread: Please Help!!!!!

I am so confused on this. I need to write an indexer returning bool that will search for the book collection for a specific title and return true if the title is in the collection; otherwise return false, and I have to use the foreach statement to loop/iterate thru the collection and ingnore any books that have a null reference, and test this functionality in the Main routine. Here are my files (this is all in C#). Sorry I am so blonde ......

Code:

Book.cs

using System;

namespace Book
{
    public class Book
    {
        private string title ;

        public string Title
        {
            get
            {
                return title ;
            }
            set
            {
                title = value ;
            }
        }

        public Book()
        {
            title = "Unknown title" ;
        }
    }
}

BookMain.cs

using System;

namespace Book
{
    public class BookMain
    {
        public BookMain()
        {
        }

        public static void Main (string [] args)
        {
            Book myBooks = new Book() ;
            Console.WriteLine ("Created " + myBooks) ;

            // Create several books
            Book [] manyBooks = new Book [5];

            // Create the individual books.  It is an error not to
            // create each reference in the array.
            for (int i = 0; i < manyBooks.Length; i++)
            {
                manyBooks [i] = new Book() ;
            }

            manyBooks[0].Title = "Tom Sawyer" ;
            manyBooks[1].Title = "Going to Town" ;
            manyBooks[2].Title = "Intro to C#" ;

            // list the books
            for (int i = 0; i < manyBooks.Length; i++)
            {
                Console.WriteLine ("Book {0} title: {1}", i + 1,
                    manyBooks [i].Title) ;
            }

            Console.Write ("\n\n") ;

            BookColl moreBooksColl = new BookColl (10);
            moreBooksColl [0] = "The best book";
            moreBooksColl [3] = "Science Fiction";

            moreBooksColl.display ("More Books Collection");
        }
    }
}

BookColl.cs

sing System;

namespace Book
{
    public class BookColl
    {
        private Book [] books ;
        
        public BookColl()
        {
        }

        public string this [int index]
        {
            // Make sure the index is within range
            get
            {
                CheckNull (index);
                if (index >= books.Length || index < 0)
                {
                    return "Unknown book number" ;
                }
                return books[index].Title ;
            }
            set
            {
                CheckNull (index);
                if (index >= books.Length || index < 0)
                {
                    return ; // out of range, can't set
                }
                books [index].Title = value ;
            }
        }

        public BookColl (int size)
        {
            books = new Book [size];
        }

        private void CheckNull (int index)
        {
            if (books [index] == null)
            {
                books [index] = new Book();
            }
        }

        public void display (string title)
        {
            Console.WriteLine ("\n========= {0} ========\n\n", title);
            foreach (Book bk in books)
            {
                if (bk == null)
                {
                    continue;
                }

                Console.WriteLine("title {0} active", bk.Title);
            }

            Console.WriteLine ("\n========= End {0} ========\n\n", title);
        }
    }
}