java基础练习题

编写Shape抽象类,包含计算图形的表面积和体积的两个方法。定义Circle类求圆柱体的表面积和体积,Rectangle类求矩形体的表面积和体积,在测试类Test里创建对象并输出结果。

Shape类：

public abstract class Shape {
    abstract double Area();
    abstract double Volume();
}

Circle类

public class Circle extends Shape{
    public double Pi = 3.14;
    int r,h;
    void Circle(){
        this.r = r;
        this.h = h;
        this.Pi = Pi;
    }
    public double Area(){
        return  2 * Pi * r * h;
    }
    public double Volume(){
        return Pi * r * r * h;
    }
}

Rectangle类

public class Rectangle extends Shape {
    int l, w, h;
    void Rectangle() {
        this.l = l;
        this.w = w;
        this.h = h;
    }
    public double Area() {
        //表面积
        return (l * w + l * h + h * w) * 2;
    }
    public double Volume() {
        //体积
        return l * w * h;
    }
}

Test类

public class Test {
    public static void main(String[] ages) {
        Rectangle s = new Rectangle();
        Circle c = new Circle();
        s.h = 3;
        s.l = 4;
        s.w = 2;
        System.out.println("长方体的表面积为：" + s.Area());
        System.out.println("长方体的体积为：" + s.Volume());
        c.Pi = 3.14;
        c.r = 2;
        c.h = 3;
        System.out.println("圆锥体的表面积为：" + s.Area());
        System.out.println("圆锥体的体积为：" + s.Volume());
    }
}

涉及技术：抽象类的定义和使用