精選文庫實驗報告課程名稱面向?qū)ο蟪绦蛟O(shè)計實驗名稱實驗三、類的繼承與多態(tài)日期2018/4/23學(xué)生學(xué)號姓名班級實驗?zāi)康模?通過本次實驗，要求學(xué)生能進(jìn)一步掌握繼承和多態(tài)的概念，熟練定義類、派生類、抽象類、抽象方法、虛擬方法和重載方法。實驗條件： 電腦一臺、能上網(wǎng)查閱資料。首先定義基本幾何圖形的基類（Shape），然后定義Shape的派生類Circle(圓形)、Square（正方形）和Triangle(三角形)。要求通過方法覆蓋來計算各種圖形的面積和周長。(提示:求三角形的面積用海倫公式：，其中a,b,c是三角形的邊長，L=(a+b+c)/2，即周長的一半。)源代碼：package ruanjian.zhaihaiyang.shiyan3;public abstract class Shape protected String name;public Shape()name=圖形類;public Shape(String name)super();=name;public String getName() return name;public void setName(String name) = name;abstract double area();abstract double length();public String toString() / TODO Auto-generated method stubreturn name+:周長和面積分別是+length()+,+area();package ruanjian.zhaihaiyang.shiyan3;public class Square extends Shape private double a;public Square(double a,String name)super(name);this.a=a;double area() / TODO Auto-generated method stubreturn Math.pow(a, 2);double length() / TODO Auto-generated method stubreturn 4*a;package ruanjian.zhaihaiyang.shiyan3;public class Circle extends Shape private double r;public Circle(double r,String name)super(name);this.r=r;double area() / TODO Auto-generated method stubreturn Math.PI*Math.pow(r, 2);double length() / TODO Auto-generated method stubreturn 2*Math.PI*r;package ruanjian.zhaihaiyang.shiyan3;public class Triangle extends Shape private double a;private double b;private double c;public Triangle (double a,double b,double c,String name)super(name);this.a=a;this.b=b;this.c=c;double area() double L=(a+b+c)/2;/ TODO Auto-generated method stubreturn Math.sqrt(L*( L-a)*( L-b)*( L-c);double length() / TODO Auto-generated method stubdouble L=(a+b+c)/2;return 2*L;package ruanjian.zhaihaiyang.shiyan3;public class ShapeDemo public static void main(String args) Shape s1=null;s1=new Circle(5, 圓形);System.out.println(s1.toString();s1= new Square(6, 正方形);System.out.println(s1.toString();s1=new Triangle(3, 4, 5, 三角形);System.out.println(s1.toString();