using System;

public class Program

{

 public static void Main(string[] args)

        {

            Subject[] subjects = new Subject[10];

​

            Subject csharp = new Subject();

            csharp.ID = 101;

            csharp.Desc = "Programming in C#";

            csharp.Students = new Student[30];

            subjects[0] = csharp;

​

            Subject sql = new Subject();

            sql.ID = 102;

            sql.Desc = "SQL Server 2012";

            sql.Students = new Student[15];

            subjects[1] = sql;

​

            Subject Java = new Subject();

            Java.ID = 103;

            Java.Desc = "Programming in Java";

            Java.Students = new Student[10];

            subjects[2] = Java;

            Student joe = new Student();

            joe.ID = 1;

            joe.FName = "Joe";

            joe.LName = "Smith";

            //associate student joe with csharp course

            csharp.Students[0] = joe;

            sql.Students[0] = joe;

​

            Student Harry = new Student();

            Harry.ID = 2;

            Harry.FName = "Harry";

            Harry.LName = "Potter";

            csharp.Students[1] = Harry;

​

​

​

​

            for (int x = 0; x < subjects.Length; x++)

            {

                if (subjects[x] != null)

                {

                    Console.WriteLine("Course id is: {0}, Course Name is: {1}", 

                        subjects[x].ID, subjects[x].Desc);

                    for (int Y = 0; Y < subjects[x].Students.Length; Y++)

                    {                        

                        if (subjects[x].Students[Y] != null)

                        {

                            Console.WriteLine("{0}, {1} {2}",

                                subjects[x].Students[Y].ID,

                                subjects[x].Students[Y].FName,

                                subjects[x].Students[Y].LName);

                        }

                    }

                    Console.WriteLine("\n");

                }

            }

            Console.ReadLine();

        }

    }

​

    public class Subject 

    {

        public int ID;

        public string Desc;

        public Student[] Students;//array of Student class

    }

    public class Student

    {

        public int ID;

        public string FName;

        public string LName;

    }