java casting

[Tiam Bezalel]

hi,
i would like to understand the result of the code below. why does it print "Good Night!" three times? i was getting the following result:

Good Night!
Good Afternoon!
Good Night!

class X {
    void greet() {
        System.out.println("Good Morning!");
    }
}
  
class Y extends X {
    void greet() {
        System.out.println("Good Afternoon!");
    }
}
  
class Z extends Y {
    void greet() {
        System.out.println("Good Night!");
    }
}
  
public class Test {
    public static void main(String[] args) {
        X x = new Z();
        x.greet(); //Line n1
        ((Y)x).greet(); //Line n2
        ((Z)x).greet(); //Line n3
    }
}

I am preparing the 1Z0-808 exam

[Stephan van Hulst]

Casting a reference doesn't change the type of the object that is being referenced. Regardless of whether you cast x to X, Y or Z, the runtime type of the object referenced by x is still a Z.