week11_1.java

interface Shape{
	final double PI = 3.14;
	void draw();
	double getArea();
	default public void redraw() {
		System.out.print("---다시 그립니다. ");
		draw();
	}
}
class Circle implements Shape{
	private int radius = 0;
	public Circle(int r) {
		radius = r;
	}
	@Override
	public void draw() {
		System.out.println("반지름이 " + radius + "인 원입니다.");
	}
	@Override
	public double getArea() {
		return radius * radius * PI;
		
	}
}
class Oval implements Shape{
	private int radius = 0;
	private int height = 0;
	public Oval(int r, int h) {
		radius = r;
		height = h;
	}
	@Override
	public void draw() {
		System.out.println(radius + 'x'+ height + "에 내접하는 타원입니다.");
	}
	@Override
	public double getArea() {
		return radius * height * PI;
		
	}
}
class Rect implements Shape{
	private int width = 0;
	private int height = 0;
	public Rect (int w, int h) {
		width = w;
		height = h;
	}
	@Override
	public void draw() {
		System.out.println(width + 'x'+ height + "크기의 사각형입니다.");
	}
	@Override
	public double getArea() {
		return width * height;
		
	}
}

public class week11_1 {

	public static void main(String[] args) {
		Shape [] list = new Shape[3];
		list[0] = new Circle(10);
		list[1] = new Oval(20, 30);
		list[2] = new Rect(10, 40);
		
		for(int i=0; i<list.length; i++) list[i].redraw();
		for(int i =0; i<list.length; i++) System.out.println("면적은 " + list[i].getArea());

	}

}