Q019. 클래스의 형변환

Question 19 : 클래스의 형변환

Given:
1. class TestA {
2.      public void start() { System.out.println(”TestA”); }
3. }
4. public class TestB extends TestA {
5.      public void start() { System.out.println(”TestB”); }
6.      public static void main(String[] args) {
7.           ((TestA)new TestB()).start();
8.      }
9. }

What is the result?

A. TestA
B. TestB
C. Compilation fails.
D. An exception is thrown at runtime.


Answer: B