public class RefEx1 {
	public static void main(String[] args) {
		Person p1 = new Person();
		Mann m1 = new Mann();

		System.out.println("runtime class of variable p1="+ p1.getClass().getName() );
		System.out.println("runtime class of variable m1="+ m1.getClass().getName() );

		p1 = m1; //up-cast is typesafe
		System.out.println("runtime class of variable p1="+ p1.getClass().getName() );
	} //main()
} //class RefEx1

class Person {
} //class Person

class Mann extends Person {
} //class Mann

class Frau extends Person {
} //class Frau