JAVA继承和多态实验报告

1、(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 ngle

2、(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 Stri ng color = while ;publicShape(Stri ng color)this . color = color;public voidsetColor(Str ing color)this . color = color;public Stri ng getColor() ret

3、ur n color ;public doublegetArea()return 0;public doublegetPerimeter()return 0;public Stri ng toStri ng()retur n color:+ color ;package Class;public class Circle exte nds Shape private double radius ;public Circle(Stri ng color,double radius) super (color);this . radius = radius;public void setRadiu

4、s( double radius)this . radius = radius;public double getRadius()return radius ;public double getCircleArea()return3.14* radius * radius ;public double getCirclePerimeter()return 3.14*2* radius ;returnThe Area is:+ getCircleArea()+ n The Perimeter is:+ getCirclePerimeter();package Class;public class

5、Recta ngleexte nds Shapeprivatedoublewidth ;privatedoubleheight ;public Recta ngle(Stri ng color,double width, doubleheight) super (color);this . width = width;this . height = height;public void setWidth( double width)this . width = width;public double getWidth() return width ;public void setHeight(

6、 double height) this . height = height;public double getHeight() retur nheight ;public doublegetRecta ngleArea()returnwidth * height ;public doublegetRecta nglePerimeter()return 2*( width + height );returnThe Area is:+ getRecta ngleArea()+ n The Perimeter is:+ getRecta nglePerimeter();package Class;

7、public classTria ngleexte ndsShapeprivatedoublea;privatedoubleb;privatedoublec;privatedoubles;publicTriangle(String color,double a, double b, double c, double s)super (color);this.a=a;this.b=b;this.c=c;this.s=s;publicvoid setA(double a)this. a = a;public double getA()return a;publicvoid setB(double

8、b)this. b = b;public double getB()return b;publicvoid setC(double c)this. c = c;returnc；public double getTria ngleArea()return Math. sqrt ( s*( s- a)*( s- b)*( s-c);public double getTria nglePerimeter()return a + b + c;public Stri ng toStri ng()return The Area is:+ getTria ngleArea()+ nThe Perimeter

9、 is:+ getTria nglePerimeter();Main 包packageMain;importClass.Shape;importClass.Circle;importClass.Recta ngle;importClass.Tria ngle;importjava.util.Sca nner;publicclass test public static voidmain( Stri ng args) Scanner in put =new Scann er(System.in );System. out .print(请输入圆的半径：”)；double radius = in

10、put. nextDouble();Circle circle =new Circle( n ull , radius);System. out .println(circle.toString();System. out .print( n 请输入矩形的宽：);double width = in put. nextDouble();System. out .print（请输入矩形的高：）;double height = in put .n extDouble();Recta ngle recta ngle =new Recta ngle(n ull , width, height);Syst

11、em. out .println(rectangle.toString();double a = in put. nextDouble();System.out .print(请输入三角形的第二条边b : ”)；double b = in put. nextDouble();System.out .print(请输入三角形的第三条边c :);double c = in put. nextDouble();double s = (a + b + c)/2;Tria ngle tria ngle =new Trian gle(n ull, a, b, c, s);System. out .println(triangle.toString();运行结果为：请齋入圆的半径：址The Acea is:314.0THe Perlme匸丄日；岛230000000000000龙请输入矩形的宽；2请输入矩形的高：3