Indexer (인덱서)
http://dis.dankook.ac.kr/lectures/hci09/entry/Indexer
Property (속성)
http://dis.dankook.ac.kr/lectures/hci09/entry/Property
Abstract Class (추상 클래스)
http://dis.dankook.ac.kr/lectures/hci09/entry/Abstract-class
Sealed Class (봉인 클래스)
http://dis.dankook.ac.kr/lectures/hci09/entry/Sealed-Class
polymorphism (다형성)
– Shape/Circle/Rectangle/Triangle/Square 클래스
– class 및 inheritance
– abstract class 및 polymorphism