Is it possible to override constructor and instance initializer?

Question

In the source below, I found that all 4 System.out.println() messages are printed.
Is it possible to have the constructor and instance intializer in ClassC overrides that of ClassB?
import java.util.*;
class ClassB {
          System.out.println("Hello");     
     ClassB() {
          System.out.println("HaHa");     
class ClassC extends ClassB {
          System.out.println("Hello1");     
     ClassC() {
          System.out.println("HaHa1");     
public class Test1 {
     public static void main(String[] args) {
          ClassC c = new ClassC();
}

Answer 1

You can't override an instance initializer, no. And when you create an object, some constructor of each of its superclasses must be called to do the creating. In your example, it's the default constructor of ClassB that's called. ClassC's constructor must call some constructor of ClassB.