public?abstract?class?Xiangz??? //定義個shape的抽象類 { public?abstract?void?ZhouChang(); //定義一個抽象的方法zhouchang public?abstract?void?MianJi(); //?定義一個抽象的方法mianji } //定義一個矩形類并繼承shape類 public?class?Rectangle?extends?Shape?? { private?int?x=8;??? //定義一個私有的變量x保存矩形的長 private?int?y=4;???? //定義一個私有的變量y保存矩形的寬 ?int?z=(x+y)*2; ?int?m=x*y; ????//復寫父類的zhouchang方法并打印輸出 public?void?ZhouChang() { System.out.println("矩形的周長為:"+z); } ??????//復寫父類的mianji方法并打印輸出 public?void?MianJi() { System.out.println("矩形的面積為："+m); } } public?class?Circular?extends?Shape { private?double?pai=3.14;?? //定義一個私有變量pai private?int?r=3;????? //定義一個私有變量r保存圓的半徑 double?z=pai*r*2; ?double?m=pai*r*r; //復寫父類的zhouchang方法并打印輸出 public?void?ZhouChang() { System.out.println("圓的周長為："+m); } //復寫父類的mianji方法并打印輸出 pubic?void?MianJi() { System.out.println("圓的面積為："+z); } } public?class?CeShi { public?static?void?main(String[]?args)? { Rectangle?x=new?Rectangle(); x.ZhouChang(); x.MianJi(); Circular?w=new?Circular(); w.ZhouChang(); w.MianJi(); } }