JAVA继承和多态实验报告

1、继承和多态实验项目名称(所属课程：Java语言程序设计)院系：专业班级：姓名：学号：实验地点：指导老师：本实验项目成绩： 教师签字： 日期： 1 .实验目的(1)掌握类的继承机制。(2)熟悉类中成员变量和方法的访问控制。(3)熟悉方法或构造方法多态性。2 .实验内容(1)模拟编写程序，理解类的继承、多态、继承和多态规则。(2)独立编程，实现类的继承和多态。3 .实验作业设计一个类Shape (图形)包含求面积和周长的area()方法和perimeter。方法以及设置颜色的方法SetColor(),并利用Java多态技术设计其子类Circle (圆形)类、Rectangle (矩形)类和Tria

2、ngle (三角形)类，并分别实现相应的求面积和求周长的方法。每个类都要覆 盖toString方法。海伦公式：三角形的面积等于s(s-a)(s-b)(s-c)的开方，其中s=(a+b+c)/2程序代码为：Class 包package Class;public class Shape private String color = "while"public Shape(String color) this .color = color;public void setColor(String color) this .color = color;public String ge

3、tC010roreturn color ;public double getArea() return 0;public double getPerimeter() return 0;public String toString() return "color:" + color;package Class;public class Circle extends Shape private double radius;public Circle(String color, double radius) super (color);this .radius = radius;

4、public void setRadius( double radius) this .radius = radius;public double getRadius() return radius ;public double getCircleArea() return 3.14* radius *radius ;public double getCirclePerimeter() return 3.14*2* radius ;public String toString()return "The Area is:" + getCircleArea()+ "n

5、The Perimeter is:" + getCirclePerimeter();package Class;public class Rectangle extends Shapeprivate double width ;private double height ;public Rectangle(String color, double width, double height) super (color);this .width = width;this .height = height;public void setWidth( double width) this .

6、width = width;public double getWidth() return width ;public void setHeight( double height) this .height = height;public double getHeight() return height ;public double getRectangleArea() return width *height ;public double getRectanglePerimeter()return 2*( width + height);public String toString()ret

7、urn "The Area is:" + getRectangleArea()+ "nThe Perimeter is:" + getRectanglePerimeter();package Class;public class Triangle extends Shapeprivate double a;private double b;private double c;private double s;public Triangle(String color, double a,double b,double c, double s) super (

8、color);this .a = a;this .b = b;this .c = c;this .s = s;public void setA( double a) this .a = a;public double getA() return a;public void setB(double b) this .b = b;public double getB() return b;public void setC( double c)this .c = c;public double getC() return c;public double getTriangleArea()return

9、 Math. sqrt(s*(s- a)*(s- b)*(s- c);public double getTrianglePerimeter() return a + b + c;public String toString()return "The Area is:" + getTriangleArea()+ "nThe Perimeter is:" + getTrianglePerimeter(); Main 包package Main;import Class.Shape;import Class.Circle;import Class.Rectan

10、gle;import Class.Triangle;import java.util.Scanner;public class test public static void main(String口 args) Scanner input = new Scanner(System. in);System.out.print("请输入圆的半径：");double radius = input.nextDouble();Circle circle = new Circle(null , radius);System. out .println(circle.toString(

11、);System.out .print( "n 请输入矩形的宽：");double width = input.nextDouble();System. out .print("请输入矩形的高：");double height = input.nextDouble();Rectangle rectangle = new Rectangle( null , width, height);System. out .println(rectangle.toString();System.out .print( "n请输入三角形的第一条边a："

12、;);double a = input.nextDouble();System.out .print("请输入三角形的第二条边b:");double b = input.nextDouble();System.out .print("请输入三角形的第三条边c：");double c = input.nextDouble();double s = (a + b + c)/2;Triangle triangle = new Triangle( null , a, b, c, s);System. out .println(triangle.toString();运行结果为：请输入圆的半役：如 The Acea is:314,0 工he Perimeter 工m;石Z.8OQ0QQQQ0QQQQQq请输入矩形的宽