chapter 07) 상속example - 도형 관련 클래스 만들기

아래의 클래스 다이어그램을 참고하여 도형 관련 클래스들을 만드시오.

원-

package practice;

public class Circle extends Shape {
	private double radius;

	public Circle(double radius) {
		this.radius = radius;
	}

	@Override
	public double area() {
		return radius * radius * Math.PI;
	}

	@Override
	public double perimeter() {
		return radius * 2 * Math.PI;
	}

	public String toString() {
		return "도형의 종류: 원, 둘레: " + perimeter() + "㎝" + ", 넓이: " + area() + "㎝";
	}
}

 

사각형 -

package practice;

public class Rectangle extends Shape {
	private double width;
	private double height;

	public Rectangle(double width, double height) {
		this.width = width;
		this.height = height;
	}

	@Override
	public double area() {
		return width * height;
	}
	@Override
	public double perimeter() {
		return (width + height) * 2;
	}

	public String toString() {
		return "도형의 종류: 사각형, 둘레: " + perimeter() + "㎝" + ", 넓이: " + area() + "㎝";
	}
}

 

삼각형 - 

package practice;

public class Triangle extends Shape {
	private double side;

	public Triangle(double side) {
		this.side = side;
	}

	@Override
	public double area() {
		return Math.sqrt(3) * side * side / 4;
	}

	@Override
	public double perimeter() {
		return side * 3;
	}

	public String toString() {
		return "도형의 종류: 삼각형, 둘레: " + perimeter() + "㎝" + ", 넓이: " + area() + "㎝";
	}
}

package practice;

public class ShapeTest {
	public static void main(String[] args) {
		Shape[] shapes = new Shape[3];
		shapes[0] = new Circle(1.0);
		shapes[1] = new Triangle(2.0);
		shapes[2] = new Rectangle(2.0,3.0);
		for(Shape shape : shapes) {
			System.out.println(shape);
		}
	}
}