class A{
double n; int m;
void f(){
System.out.printf("子类继承方法f(),n=%f,m=%d\n",n,m);
}
void g(){
System.out.printf("你好,n=%f,m=%d\n",n,m);
}
}
class B extends A{
int n=12;
void g(){
System.out.printf("子类重写方法g(),n=%d,m=%d\n",n,m);
}
void cry(){
System.out.printf("子类新增的方法,n=%d,m=%d\n",n,m);
}
}
public class Example5_8{
public static void main(String arg[]){
A a=new B();
a.n=0.618;
a.m=200;
a.f();
a.g();
B b=(B)a; b.n=555; b.cry();
}
}