阅读下列程序,写出程序运行结果。class A1{public void f(int aa, int bb){System. out. print
阅读下列程序,写出程序运行结果。
class A1
{
public void f(int aa, int bb)
{
System. out. println(aa+bb) ;
}
}
class A2 extends A1
{
public void f(int aa, int bb)
{
System. out. println(aa-bb) ;
}
}
public class C3201 extends A2
{
public void f(int aa, int bb)
{
System. out. println(aa*bb) ;
}
public static void main(String[] args)
{
A1 a=new Al() ;
A1 a1=new A2() ;
A2 a2=new C3201() ;
a. f(20, 10) ;
a1. f(20, 10) ;
a2. f(20, 10) ;
}
}