父類：

package com.imocc

public abstract class shape {

public abstract void l();

public abstract void s();

}

子類：rectangle

package com.imocc;

public class rectangle extends shape {

public void l(int a,int b){

System.out.println("長方形的周長是："+(a+b)*2);

}

public void s(int a,int b){

System.out.println("長方形的面積是："+a*b);

}

}

子類circle：

package com.imocc;

public class circle extends shape {

double π=3.14;

public void l(int r){

double m=2*π*r;

System.out.println("圓形的周長是："+m);

}

? ? public void s(int r){

? ? double n=π*r*r;

? ? System.out.println("圓形的面積是："+n);

? ? }

}

inital；

package com.imocc;

import java.util.Scanner;

public class inital {

public static void main(String[] args) {

shape rec=new rectangle();

Scanner input=new Scanner(System.in);

System.out.println("請輸入長方形的長a：");

int a=input.nextInt();

System.out.println("請輸入長方形的寬b：");

int b=input.nextInt();

rec.l(a,b);

rec.s(a,b);

shape c=new circle();

Scanner input2=new Scanner(System.in);

System.out.println("請輸入圓形的半徑r:");

int r=input2.nextInt();

c.l(r);

c.s(r);

// TODO Auto-generated method stub

}

}