父類

package cxl.lxb;

public abstract class Shape {

public abstract void mianji();

public abstract void zhouchang();

}

子類

package cxl.lxb;

public class Rectangle extends Shape {

@Override

public void mianji() {

// TODO Auto-generated method stub

double sum=40;

System.out.println("矩形面積為"+sum);

}

@Override

public void zhouchang() {

// TODO Auto-generated method stub

int;

System.out.println("矩形周長為"+lang);

}

}

子類

package cxl.lxb;

public class Circle extends Shape {

@Override

public void mianji() {

// TODO Auto-generated method stub

double sum=90;

System.out.println("圓形面積為"+sum);

}

@Override

public void zhouchang() {

// TODO Auto-generated method stub

double;

System.out.println("圓形周長為"+lang);

}

}

入口類

package cxl.lxb;

public class Initail {

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

? ? ? Shape sha=new Rectangle();

? ? ? sha.mianji();

? ? ? sha.zhouchang();

? ? ? Shape sha1=new Circle();

? ? ? sha1.mianji();

? ? ? sha1.zhouchang();

}

}