[java]_예제_추상클래스 & 상속_01

abstract class Shape {
	String type;
	Shape(String type) {
		this.type = type;
	}
	abstract double area();
	abstract double length();
}

class Circle extends Shape{
	int r;
	Circle(int r) {
		super("원");
		this.r = r;
	}
	
	@Override
	double area() {
		return r * r * Math.PI;
	}
	
	@Override
	double length() {
		return 2 * r * Math.PI;
	}
	
	@Override
	public String toString() {
		return "Shape [type=" + type + ", r=" + r + "]";
	}
	

}

class Rectangle extends Shape {
	int width, height;
	Rectangle(int width, int height) {
		super("사각형");
		this.width = width;
		this.height = height;
	}

	@Override
	double area() {
		return width * height;
	}
	@Override
	double length() {
		return 2 * (width + height);
	}
	@Override
	public String toString() {
		return "Shape [type=" + type + ", width=" + width + ", height=" + height+"]";
	}
}

public class ShapeEx {
	public static void main(String[] args) {
		Shape[] shapes = new Shape[2];
		shapes[0] = new Circle(10);
		shapes[1] = new Rectangle(5,5);
		for(Shape s : shapes) {
			System.out.println(s);
			System.out.println("넓이:"+s.area()+" 둘레:"+s.length());
		}
	}
}