test java extends cast 繼承 轉型

/** CastTest.java */

class A{}

class B extends A

{

    public void f()

    {

        System.out.println("f() in B");

    }

}

public class CastTest

{

    public static void main(String args[])

    {

        A a = new B();

        ((B)a).f();

        (B)a.f(); //  error: not a statement

        a.f();

        /* error: cannot find symbol

                 a.f(); // error

                 ^

           symbol:   method f()

           location: variable a of type A */

    }

   

}

static method: compile-time binding
instance method: run-time binding
http://www.javaprogrammingforums.com/java-programming-tutorials/3117-static-fields-inheritance.html
http://www.artima.com/forums/flat.jsp?forum=1&thread=3620

待查: static block