1 package com.四邊形;

2 public class Quadrangle {
3 ?private int? nextIndex=0;
? 4 private Quadrangle[] qtext=new Quadrangle[6];
?5 public void draw(Quadrangle q) {
??6 if (nextIndex<qtext.length) {
???7 qtext[nextIndex]=q;
???8 System.out.println(nextIndex);
??9?nextIndex++;
??}
??
?}

?10 public static void main(String[] args) {
??// TODO Auto-generated method stub
??11Quadrangle q=new Quadrangle();
??//Parallelogramgle p=new Parallelogramgle();
??//Square s=new Square();
??12 q.draw(new Parallelogramgle());
??13 q.draw(new Square());
??
??

?}

?14 public class Parallelogramgle extends Quadrangle{
?15 public Parallelogramgle() {
??16 System.out.println("平行四邊形");
?}
}
17 public class Square extends Quadrangle{
?18 public Square() {
??19 System.out.println("正方形");
?}
}
?
}