class Point : IEquatable<Point>, IComparable<Point>
{
// static member field
protected static int count = 0;

// instance member field
protected int x, y;

// property
public int X
{
get { return this.x; }
set { this.x = value; }
}

public int Y
{
get { return this.y; }
set { this.y = value; }
}

public static int Count
{
get { return count; } // error: this.count 는 사용할 수 없음
}

// constructor & destructor
public Point() : this(0, 0) { }
public Point(int x, int y) { this.x = x; this.y = y; count++; }
~Point() { count–; }

// method
public void SetPosition(int x, int y) { this.x = x; this.y = y; }
public void Move(int x, int y) { this.x += x; this.y += y; }

// ToString method override
public override string ToString() { return (String.Format(“({0}, {1})”, x, y)); }
// virtual method
public virtual void Print() { Console.WriteLine(“X={0} Y={1}”, x, y); }
// static method
public static int GetCount() { return count; }
// operator++ overload
public static Point operator++(Point p) { ++p.x; ++p.y; return p; }
// operator== overload
public static bool operator==(Point p1, Point p2) { return p1.Equals(p2); }
// operator!= overload
public static bool operator!=(Point p1, Point p2) { return !p1.Equals(p2); }
public override int GetHashCode() { return x ^ y; }
public override bool Equals(object obj)
{
if (!(obj is Point))
return false;
return Equals((Point)obj);
}

// IEquatable
public bool Equals(Point other)
{
if (this.x == other.x && this.y == other.y)
return true;
return false;
}

// IComparable
public int CompareTo(Point other)
{
if (this.x > other.x)
{
return 1;
}
else if (this.x < other.x)
{
return -1;
}
else
{
return 0;
}
}
}

class Point3D : Point, IEquatable<Point3D>
{
// instance member field
protected int z;

// property
public int Z
{
get { return this.z; }
set { this.z = value; }
}

// constructor & destructor
public Point3D() : this(0, 0, 0) { }
public Point3D(int x, int y, int z) : base(x, y) { this.z = z; }
~Point3D() { }

public void SetPosition(int x, int y, int z) { base.SetPosition(x, y); this.z = z; }
public void Move(int x, int y, int z) { base.Move(x, y); this.z += z; }

// override ToString method
public override string ToString() { return (String.Format(“({0}, {1}, {2})”, x, y, z)); }
// overrided method
public override void Print() { Console.WriteLine(“X={0} Y={1} Z={2}”, x, y, z); }
// operator++ overload
public static Point3D operator++(Point3D p) { ++p.x; ++p.y; ++p.z; return p; }
// operator== overload
public static bool operator ==(Point3D p1, Point3D p2) { return p1.Equals(p2); }
// operator!= overload
public static bool operator !=(Point3D p1, Point3D p2) { return !p1.Equals(p2); }
public override int GetHashCode() { return x ^ y ^ z; }
public override bool Equals(object obj)
{
if (!(obj is Point3D))
return false;
return Equals((Point3D)obj);
}

// IEquatable
public bool Equals(Point3D other)
{
if (this.x == other.x && this.y == other.y && this.z == other.z)
return true;
return false;
}
}

class PointTest
{
// pass-by-value (value type)
static void Swap(int p1, int p2)
{
int p;
p = p1;
p1 = p2;
p2 = p;
}

// pass-by-reference (value type)
static void Swap(ref int p1, ref int p2)
{
int p;
p = p1;
p1 = p2;
p2 = p;
}

// pass-by-value (reference type)
static void Swap(int[] p1, int[] p2)
{
int[] p;
p = p1;
p1 = p2;
p2 = p;
}

// pass-by-value (reference type)
static void Swap(ref int[] p1, ref int[] p2)
{
int[] p;
p = p1;
p1 = p2;
p2 = p;
}

static void Swap(ref Point p1, ref Point p2)
{
Point p;
p = p1;
p1 = p2;
p2 = p;
}

static void Swap(ref Point3D p1, ref Point3D p2)
{
Point3D p;
p = p1;
p1 = p2;
p2 = p;
}

static void Main(string[] args)
{
// value type: pass-by-value/pass-by-reference
int i = 5, j = 10;
Console.WriteLine(“Before: i={0}, j={1}”, i, j);

Swap(i, j);
Console.WriteLine(“After integer pass-by-value swap: i={0}, j={1}”, i, j);

Swap(ref i, ref j);
Console.WriteLine(“After integer pass-by-reference Swap: i={0}, j={1}”, i, j);

// reference type: pass-by-value/pass-by-reference
int[] arr1 = { 1, 2, 3 };
int[] arr2 = { 4, 5, 6, 7, 8 };
Console.WriteLine(“Before array pass-by-value swap: “);
Console.Write(“arr1: “);
foreach (int a in arr1)
Console.Write(“{0} “, a);
Console.WriteLine();
Console.Write(“arr2: “);
foreach (int a in arr2)
Console.Write(“{0} “, a);
Console.WriteLine();

Swap(arr1, arr2);
Console.WriteLine(“After array pass-by-value swap: “);
Console.Write(“arr1: “);
foreach (int a in arr1)
Console.Write(“{0} “, a);
Console.WriteLine();
Console.Write(“arr2: “);
foreach (int a in arr2)
Console.Write(“{0} “, a);
Console.WriteLine();

Swap(ref arr1, ref arr2);
Console.WriteLine(“After array pass-by-reference swap: “);
Console.Write(“arr1: “);
foreach (int a in arr1)
Console.Write(“{0} “, a);
Console.WriteLine();
Console.Write(“arr2: “);
foreach (int a in arr2)
Console.Write(“{0} “, a);
Console.WriteLine();

Console.Write(“p1: “);
Point p1 = new Point();
Console.Write(“p2: “);
Point p2 = new Point();

// Point
p1.SetPosition(10, 10); // 변수 값 지정
Console.Write(“p1 SetPosition: “);
p1.Print(); // 현재 좌표 출력
p1.Move(20, 50); // 좌표 변경 (점의 위치 이동)
Console.Write(“p1 Move: “);
p1.Print(); // 현재 좌표 출력
Console.WriteLine(“p1=” + p1);

p2.SetPosition(20, 30); // 변수 값 지정
Console.Write(“p2 SetPosition: “);
p2.Print(); // 현재 좌표 출력

//포인터 객체 교환함수 호출
Console.WriteLine(“\nSwap”);
Swap(ref p1, ref p2);
Console.WriteLine(“p1: {0}”, p1);
Console.WriteLine(“p2: {0}”, p2);

Console.WriteLine();
Console.WriteLine(“p1.m_nX={0}, p1.m_nY={1}, Point.GetCount()={2}”, p1.X, p1.Y, Point.Count);
Console.WriteLine(“p2.m_nX={0}, p2.m_nY={1}, Point.GetCount()={2}”, p2.X, p2.Y, Point.Count);

// Point3D
Console.Write(“p3: “);
Point3D p3 = new Point3D();
Console.Write(“p4: “);
Point3D p4 = new Point3D();

Console.WriteLine();
p3.SetPosition(10, 20);
Console.Write(“p3 SetPosition: “);
p3.Print(); // 현재 좌표 출력
p3.SetPosition(30, 40, 50);
Console.Write(“p3 SetPosition: “);
p3.Print(); // 현재 좌표 출력
++p3;
Console.Write(“++p3: “);
p3.Print(); // 현재 좌표 출력
p3.Move(20, 30, 40); // 좌표 변경 (점의 위치 이동)
Console.Write(“p3 Move: “);
p3.Print(); // 현재 좌표 출력
p3.Move(10, 10); // 좌표 변경 (점의 위치 이동)
Console.Write(“p3 Move: “);
Console.WriteLine(p3); // p3는 Point클래스의 ToString이 호출

Console.WriteLine();
p4.SetPosition(100, 200, 300);
Console.Write(“p4 SetPosition: “);
p4.Print(); // 현재 좌표 출력
p4.Move(10, 10, 10); // 좌표 변경 (점의 위치 이동)
Console.Write(“p4 Move: “);
p4.Print(); // 현재 좌표 출력

//포인터 객체 교환함수 호출
Console.WriteLine(“\nSwap”);
Swap(ref p3, ref p4);
Console.WriteLine(“p1: {0}”, p3);
Console.WriteLine(“p2: {0}”, p4);

Console.WriteLine();
Console.WriteLine(“p3.m_nX={0}, p3.m_nY={1}, p3.m_nZ={2}, Point.GetCount()={3}”, p3.X, p3.Y, p3.Z, Point.GetCount());
Console.WriteLine(“p4.m_nX={0}, p4.m_nY={1}, p4.m_nZ={2}, Point.count={3}”, p4.X, p4.Y, p4.Z, Point.Count);

if (p3 == p4)
Console.WriteLine(“p3 == p4”);
if (p3 != p4)
Console.WriteLine(“p3 != p4”);

Console.Write(“p5: “);
Point p5 = p3;
p5.Print(); // 현재 좌표 출력 p5는 Point3D – polymorphism
Console.Write(“p6: “);
Point p6 = new Point3D(110, 210, 310); // p6도 Point3D
p6.Print(); // Point3D의 Print가 호출 (late binding) – polymorphism
Point3D p7 = (Point3D)p5;
Console.WriteLine(p7); // p7는 Point3D클래스의 ToString이 호출
if (p7 == p5)
Console.WriteLine(“p7 == p5”);
if (p7 == p6)
Console.WriteLine(“p7 == p6”);
}
}

string str = “Hi, Welcome to HCI Programming II! Hi”;
Console.WriteLine(“str의 substring(3) {0}”, str.Substring(3)); // ” Welcome to HCI Programming II! Hi” 3번째 위치에서 떼어냄

Console.WriteLine(“str의 substring(14, 20) {0}”, str.Substring(14,20)); // ” HCI Programming II!” 14번째 위치에서부터 20개 만큼 떼어냄

    class Person
    {
        private string name; // 파상클래스에 상속 안됨
        protected int age; // 파생클래스에 상속 됨

        public Person() : this(“HCI”, 20)
        {
        }

        public Person(string name, int age)
        {
            this.name = name;
            this.age = age;
        }

        protected string GetName() // 파생클래스에 상속 안됨
        {
            return name;
        }

        protected void SetName(string name) // 파생클래스에 상속 안됨
        {
            this.name = name;
        }

        public void Print()
        {
            Console.WriteLine(“Person Name: {0} Age: {1}”, name, age);
        }
    }

    class Student : Person
    {
        int id;

        public Student() // public Student : base()와 같은 의미, 생성자는 상속안됨
        {
            id = 5208;
        }

        public Student(string name, int age, int id) : base(name, age)
        {
            this.id = id;
        }

        public void Print()
        {
            Console.WriteLine(“Student Name: {0} Age: {1} Id: {2}”, GetName(), age, id);
        }
    }

   class Program
    {
        static void Main(string[] args)
        {
            Person p = new Person();
            p.Print();

            Person p1 = new Person(“HCI2~~~~~~~~~~”, 2013);
            p1.Print();

            Student s = new Student();
            s.Print();

            Student s1 = new Student(“학생들~~”, 24, 555);
            s1.Print();
        }
    }

    class Car
    {
        // member field
        //string name;
        //int year;
        /*
        public string Name
        {
            get
            {
                return this.name;
            }
            set
            {
                this.name = value;
            }
        }
        public int Year
        {
            get
            {
                return this.year;
            }
            set
            {
                this.year = value;
            }
        }
        */

        // property
        public string Name
        {
            get;
            set;
        }
        public int Year
        {
            get;
            set;
        }

        // constructor
        public Car() : this(“Avante”, 2013)
        {
        }

        public Car(string name, int year)
        {
            this.Name = name;
            this.Year = year;
        }

        // method
        public void Print()
        {
            Console.WriteLine(“자동차 {0} 년도 {1}”, this.Name, this.Year);
        }
    }

  class Program
    {
        static void Main(string[] args)
        {
            Car c1 = new Car();
            c1.Print();
            c1.Name = “Accent”;
            c1.Print();
            Console.WriteLine(c1.Name);

            Car c2 = new Car(“Sonata”, 2012);
            c2.Print();
        }