C# Defining a Structure

struct Books
{
   public string title;
   public string author;
   public string subject;
   public int book_id;
};

The following program shows the use of the structure:

using System;
   
struct Books
{
   public string title;
   public string author;
   public string subject;
   public int book_id;
};

public class testStructure
{
   public static void Main(string[] args)
   {

      Books Book1;        /* Declare Book1 of type Book */
      Books Book2;        /* Declare Book2 of type Book */

      /* book 1 specification */
      Book1.title = "C# Programming";
      Book1.author = "Ali Rabjar";
      Book1.subject = "C# Programming";
      Book1.book_id = 123456;

      /* book 2 specification */
      Book2.title = "Billing";
      Book2.author = "Ali";
      Book2.subject =  "Billing";
      Book2.book_id =56789123;

      /* print Book1 info */
      Console.WriteLine( "Book 1 title : {0}", Book1.title);
      Console.WriteLine("Book 1 author : {0}", Book1.author);
      Console.WriteLine("Book 1 subject : {0}", Book1.subject);
      Console.WriteLine("Book 1 book_id :{0}", Book1.book_id);

      /* print Book2 info */
      Console.WriteLine("Book 2 title : {0}", Book2.title);
      Console.WriteLine("Book 2 author : {0}", Book2.author);
      Console.WriteLine("Book 2 subject : {0}", Book2.subject);
      Console.WriteLine("Book 2 book_id : {0}", Book2.book_id);    

      Console.ReadKey();

   }
}

it produces following result:

Book 1 title : C# Programming
Book 1 author : Ali Rabjar
Book 1 subject : C# Programming
Book 1 book_id : 123456
Book 2 title : Billing
Book 2 author : Ali
Book 2 subject : Billing
Book 2 book_id : 56789123