using System;

class Student

{

    //1. [Code] Create (string) NAME: use auto-implementation

    public string NAME {get; set;}

    //2. [Code] Create (int) AGE: use auto-implementation

    public int AGE {get; set;}

    //3. [Code] (double) Create a private field (_gpa) and a public properties (GPA)

    //Rule: gpa should not be negative.

    private double _gpa;

    public double GPA

    {

        get

        {

            return _gpa;

        }

        set

        {

            if(value >= 0)

            {

                _gpa = value; 

            }

            else 

            {

                _gpa = 3; //just set a random value if instructions don't specify. no need to return error msg

            }   

        }

    }

    //4. [Code] Create the first constructor (no parameter)

    public Student() 

    {

    }

    //5. [Code] Create the second constructor (3 parameters to set up those 3 properties)

    public Student(string strname, int iage, double dgpa) //constructor inputs

    {

        NAME = strname;

        AGE = iage;

        GPA = dgpa;

    }

​

    //6. [Code] Function ShowGPA

    //Get (regular, or adjusted) GPA

    //Input: string strType

    //Output: return a double type 

    //If strType equals to "adjusted", return GPA x 1.15

    //For other cases, return GPA

    public double ShowGPA(string strType)

    {

        double dReturn = 0; //declare outcome

        if(strType == "adjusted")

        {

            dReturn = GPA*1.15; //reference public

        }

        else 

        {

            dReturn = GPA;

        }

        return dReturn; //must return a value

    }

    //7. [Code] Function LuckyDraw

    //Check whether student is lucky or not.

    //Input: no

    //Output: return a bool type 

    //return true if the AGE is divisible by 4; false, otherwise (hint: %)

    public bool bIsLucky()

    {

        //return AGE % 4 == 0; (alternative easier way)

        bool bReturn; //initialize outcome variable

        if(AGE % 4 == 0)

        {

            bReturn = true; 

        }

        else 

        {

            bReturn = false;

        }

        return bReturn;

    }

}

public class Program

{

    //I wrote a function for you

    public static void CallFunction(int iInput, ref double dInput)  //What does static mean???????? //explain pass by value, pass by reference

    {

        iInput = iInput + 1;

        dInput = dInput + 1;

    }

    public static void Main()

    {

        //I set up some values for you.

        string strName = "Mary";

        int iAge = 18;

        double dGPA = 3.6;

        //8. [Code] Create a student object by using the value above.

        Student student1 = new Student(strName, iAge, dGPA);

        //9. [Code] Call ShowGPA("regular")

        Console.WriteLine(student1.ShowGPA("regular"));

        //10. [Code] Call ShowGPA("adjusted")

        Console.WriteLine(student1.ShowGPA("adjusted"));

        //11. [Code] Call LuckyDraw

        Console.WriteLine(student1.bIsLucky());

        Console.WriteLine("=================");

        ///12. ***[Write your answer in the following comments]***

        Console.WriteLine("Age:{0}, GPA:{1}",iAge, dGPA);

        //What is the output of the previous code?

        //***Answer: Age:18, GPA:3.6

        CallFunction(iAge, ref dGPA);

        //13. ***[Write your answer in the following comments]***

        Console.WriteLine("Age:{0}, GPA:{1}",iAge, dGPA);

        //What is the output of the previous code?

        //***Answer: Age:18, GPA:4.6

        //Why are the value different (write down the keywords)?

        //***Answer: call by reference changes original value for GPA

    }

}