【年少的风】java测试抽象类，继承

 

abstract class Shap {//抽象类

    protected double width;
    protected double length;

    Shap(final double width, final double length) {
        this.width = width;
        this.length = length;
    }

    abstract double area();//抽象方法
}

class Square extends Shap {

    Square(final double width, final double length) {
        super(width, length);
    }

    double area() {
        return width * length;
    }
}

class Triangle extends Shap {

    Triangle(final double width, final double length) {
        super(width, length);
    }

    double area() {
        return width*length/2;
    }
}

public class CalculateArea {

    public static void main(String[] args) {

        Square square = new Square(20,10);
        System.out.println("\n正方形的面积为：" + square.area());

        Triangle triangle = new Triangle(20,10);
        System.out.println("\n三角形的面积为：" + triangle.area());




    }

}