import kr.poly.A; public class TPC28 { public static void main(String[] args) { A a=new A(); a.display(); //System.out.println(a.toString()); System.out.println(a); // Object-->toString() : kr.poly.A@279f2327 Object o=new A(); // upcasting ((A)o).display(); System.out.println(o.toString()); } }