public?abstract?class?Shape{
????public?abstract?void?Circle();
????public?abstract?void?Area();
}
public?class?Rectangle?extends?Shape{
????int?a=2;
????int?b=3;
????public?void?Circle();
????public?void?Area();
????System.out.println("矩形的周長="+2*(a+b));
????System.out.println("矩形的面積="+a*b);
}
public?class?Circle?extends?Shape{
????double?r=3.15;
????double?P=3.14;
????public?void?Circle();
????public?void?Area();
????System.out.println("圓形的周長="+2Pr);
????System.out.println("圓形的面積="+Pr*r);
}
????public?static?void?main(Spring[]?args){
????????Shape?i=new?Rectangle();
????????i.Circle();
????????i.Area();
????????Shape?j=new?Circle();
????????j.Circle();
????????j.Area();
????}
2016-05-03
abstract?class?Shape{ ????public?abstract?void?Circle(); ????public?abstract?void?Area(); } class?Rectangle?extends?Shape{ ????int?a=2; ????int?b=3; ????public?void?Circle(){ ????System.out.println("矩形的周長="+2*(a+b)); ????} ????public?void?Area(){ ????System.out.println("矩形的面積="+a*b);???? ????} } class?Circle?extends?Shape{ ????double?r=3.15; ????double?P=3.14; ????public?void?Circle(){ ????System.out.println("圓形的周長="+2*P*r); ????} ????public?void?Area(){ ????System.out.println("圓形的面積="+P*r*r);????? ????} } public?class?Test{???? ????public?static?void?main(String[]?args){ ????????Shape?i=new?Rectangle(); ????????i.Circle(); ????????i.Area(); ????????Shape?j=new?Circle(); ????????j.Circle(); ????????j.Area(); ????} }2016-04-30
子類輸出語句要放在Cirlcle()和area(）方法的大括號里
public void zhouzhang() {
??// TODO Auto-generated method stub
??int zz=(a+b)*2;
??System.out.println("矩形周長為："+zz);
?}
2016-04-10
main函數應該放在一個public類里