河南省建设教育协会网站,程序源代码下载网站,免费手机虚拟机,360网站 备案这个星期主要是学习了Java中类的继承问题.继承就是由已有的类创建新类,通过子类继承父类的方法,实现一些功能.下面就是老师布置作业的其中一个:定义父类圆#xff0c;通过继承#xff0c;获得子类球、圆锥、圆柱#xff0c;子类具有计算体积的功能。1)新建文件夹Test1#…这个星期主要是学习了Java中类的继承问题.继承就是由已有的类创建新类,通过子类继承父类的方法,实现一些功能.下面就是老师布置作业的其中一个:定义父类圆通过继承获得子类球、圆锥、圆柱子类具有计算体积的功能。1)新建文件夹Test12)定义父类CircleCircle具有保护成员变量半径r并提供成员方法setR、getArea和带参数的构造函数3)子类球Ball具有获得体积的成员方法getValume4)子类圆锥Cone、圆柱Cylinder具有私有的成员变量高high、设置高的成员方法setHigh()和获得体积的getValume5)3个子类都提供带参数的构造函数6)3个子类在重设半径后应获得正确的体积7)编写测试类进行测试代码:Circle.javapackage test3;public class Circle {public static void main(String[] args) {// TODO Auto-generated method stub}protected double r;public void setR(double r) {this.r r;}public double getArea() {return 3.14*r*r;}//public Circle(double r) {//super();//this.r r;//}public Circle() {super();// TODO Auto-generated constructor stub}}Ball.javapackage test3;import java.util.Scanner;public class Ball extends Circle{public static void main(String[] args) {// TODO Auto-generated method stubreader new Scanner(System.in);Ball ball new Ball();double r;System.out.println(请输入圆的半径);r reader.nextDouble();ball.setR(r);System.out.println(体积 ball.getValumn());}private static Scanner reader;public double getValumn() {return getArea()*r*4/3;}public Ball() {super();// TODO Auto-generated constructor stub}}Cone.javapackage test3;import java.util.Scanner;public class Cone extends Circle{//public Cone(double r) {//super(r); TODO Auto-generated constructor stub//}//private double valumn;private double high;private static Scanner reader;public void setHigh(double high) {this.high high;}public double getValumn() {return getArea() *high/3;}public Cone() {super();// TODO Auto-generated constructor stub}public static void main(String[] args) {// TODO Auto-generated method stubreader new Scanner(System.in);Cone cone new Cone();double high,r;System.out.println(请输入圆锥的高);high reader.nextDouble();System.out.println(请输入圆锥的半径);r reader.nextDouble();cone.setHigh(high);cone.setR(r);System.out.println(体积 cone.getValumn());}}Cylinder.javapackage test3;import java.util.Scanner;public class Cylinder extends Circle{public static void main(String[] args) {// TODO Auto-generated method stubreader new Scanner(System.in);Cylinder cy new Cylinder();double r,high;System.out.println(请输入的高);high reader.nextDouble();System.out.println(请输入半径);r reader.nextDouble();cy.setHigh(high);cy.setR(r);System.out.println(体积 cy.getValumn());}private double high;private static Scanner reader;public void setHigh(double high) {this.high high;}public double getValumn() {return getArea() *high;}public Cylinder() {super();// TODO Auto-generated constructor stub}}Java中类的继承,更多的可以查看http://www.cnblogs.com/dolphin0520/p/3803432.html,这里有详细的介绍,我大致就是看这个学习的.---------------------作者yang_tang来源CSDN原文https://blog.csdn.net/yang_tang/article/details/78070791?utm_sourcecopy版权声明本文为博主原创文章转载请附上博文链接
