SCJP - 22 - Given Example

Which, inserted at line 9, will compile? (Choose all that apply.)

A. Beagle b2 = (Beagle) dog1;
B. Beagle b3 = (Beagle) dog2;
C. Beagle b4 = dog2;
D. None of the above statements will compile

Answer:

A and B are correct. However, at runtime, A will throw a ClassCastException because
dog1 refers to a Dog object, which can’t necessarily do Beagle stuff.

C and D are incorrect based on the preceding.
(Objective 5.2).
==

class Dog { }
class Beagle extends Dog { }

class Kennel {
public static void main(String [] arfs) {
Beagle b1 = new Beagle();
Dog dog1 = new Dog();
Dog dog2 = b1;
// insert code here
}
}