2_7.상속관계에서 클래스간의 형변환

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
 
namespace cshapExTwo10
{
    class Program
    {
        static void Main(string[] args)
        {
            // 상속관계의 클래스간 형변환
 
            Console.WriteLine("1--------------------------------");
            Human human1 = new Human();
            human1.showInfo();
           
            Programmer programmer1 = new Programmer();
            programmer1.programming();
            programmer1.showInfo();
 
            Designer designer1 = new Designer();
            designer1.design();
            designer1.showInfo();
 
            //2
            Console.WriteLine("2--------------------------------");
            Human human2 = new Programmer();
            human2.showInfo();
 
            Programmer programmer2 = (Programmer)human2;
            programmer2.showInfo();
            programmer2.programming();
 
            human2 = new Designer();
            Designer designer2 = (Designer)human2;
            designer2.showInfo();
            designer2.design();
 
            //3
            Console.WriteLine("3--------------------------------");
            Human human3 = new Programmer();
            Teacher tc3 = new Teacher();
            tc3.teach(human3);
 
            human3 = new Designer();
            tc3.teach(human3);
 
            Console.ReadKey();
        }
    }
 
    class Human
    {
        public void showInfo()
        {
            Console.WriteLine("Human");
        }
    }
 
    class Programmer : Human
    {
        public void programming()
        {
            Console.WriteLine("Programmer");
        }
    }
 
    class Designer : Human
    {
        public void design()
        {
            Console.WriteLine("Designer");
        }
    }
 
    class Teacher
    {
        public void teach(Human h)
        {
            h.showInfo();
        }
    }
}
 

------------------------------결과창------------------------------

1--------------------------------

Human

Programmer

Human

Designer

Human

2--------------------------------

Human

Human

Programmer

Human

Designer

3--------------------------------

Human

Human