using System;

//Professor Class

public class Professor

{

    // [Code] Define Fields

    public string ProfessorName;

    // [Code] Define Property Age

    // Make sure Age is between 18 and 70

    // If Age violates the rule, set the default value as 30

    private int _Age;

    public int Age

    {

        get { return _Age; }

        set 

        { 

            if (18 <= value && value <= 70) 

                _Age = value;

            else

                _Age = 30; 

        }

    }

    // [Code] Define Property Degree

    // The degree's value should only equal to "master" or "phd".

​

    private string _Degree;

    public string Degree

    {

        get { return _Degree; } 

        set 

        {

            if (value == "phd" || value == "master")

                _Degree = value; 

            else

            {

                Console.WriteLine("Degree {0} is invalid", value);

                _Degree = "master";

            }

        }

    }

    // [Code] Constructor

    public Professor()

    {

        Age = 18;

        // Degree = "";

    }

}

​

//Course Class

public class Course

{

    // [Code] Define Fields

    public string CourseName;

    // [Code] Properties CourseID

    // Make sure CourseID has exactly 4 characters

​

    private string _id;

    public string CourseID

    {

        get { return _id;}

        set 

        { 

            if (value.Length == 4)

                _id = value;

            else {}

        }

    }

    // [Code] Properties ClassLimit

    // Make sure ClassLimit is under 50

    private int limit;

    public int ClassLimit

    {

        get

        {

            return limit;

        }

        set 

        {

            if (value < 1 ) limit = 1;

            else if (value > 50) limit = 50;

            else limit = value; 

        }

    }

​

    // [Code] Constructor

    public Course()

    {

    }

}

​

public class Program

{

    public static void Main()

    {

        //[Code] Create an object ProfessorTuna

        // ProfessorName: Tuna

        // Age: 99

​

        Professor t = new Professor();

        t.ProfessorName = "Tuna";

        Console.WriteLine("Name= {0}", t.ProfessorName);

        Console.WriteLine("Age= {0}", t.Age);

        t.Age = 99;

        Console.WriteLine("Age= {0}", t.Age);

        t.Degree = "postdoc";

        Console.WriteLine("Degree= {0}", t.Degree); 

        //[Code] Create an object CourseS308

        // CourseID: S308

        // CourseName: C#

        // ClassCapacity: 21

​

        Course c = new Course();

        c.CourseID = "S308";

        c.CourseName = "C#";

        c.ClassLimit = 21;

        c.ClassLimit = 100;

        Console.WriteLine(c.ClassLimit);

        // [Code] Show professor's age and course capacity

        // What happens if the age is greater than 70?

    }

}