Inheritance - instance variable initialization

Question

Hi all.
I have a question regarding inherited instance variables.
class Animal {
   int weight;
   int age = 10;
class Dog extends Animal {
   String name;
class Test {
   public static void main(String[] args) {
      new Dog();
}This is just an arbitrary code example.
When new Dog() is invoked, I understand that it's instance variable "name" is give the default
type value of null before Dog's default constructor's call to super() is invoked.But Im a little perplexed about
Animals instance variables. I assume that like Dog, Animals instance variables are given their default type values
of 0 & 0 respectively, before Animals invocation of super(); What im unclear about is that at the point that weight and age are given their default type values, are Dog's inherited weight and age variables set to 0 aswell at that exact moment? Or are Dog's inherited weight and age variables only assigned their values after Animals constructor fully completes because initialization values are only assigned to a classes instance variables after it's call to super().
Many thanks & best regards.

Answer 1

Boeing-737 wrote:
calvino_ind wrote:
Boeing-737 wrote:
newark wrote:
why not throw in some print statements and find out?Super() or this() have to be the very first statement in a constructor..
Also you cannot access any instance variables until after super or this.
:-S
Kind regardsbut if you add the "print" statement in animal constructor, you can easily see what happened to the attributes of Dog ; that s the trick to print "before" super()You can never add a print before super(). It's a rule of thumb, super() and this() must always be the first statements
in a constructor, whether added implicitly by the compiler or not. In this case there are 2 default constructors (inserted by the compiler), each with a super() invocation. Even if i added them myself and tried to print before super(), the compiler would complain.
Thanks for the help & regards.you didn't understand what i meant ; take a look at that:
class Animal {
   int weight;
   int age = 10;
   public Animal() {
       Dog thisAsADog = (Dog) this;
      System.out.println(thisAsADog.name);
      System.out.println(thisAsADog.x);
class Dog extends Animal {
   String name;
   int x = 10;
public class Test {
   public static void main(String[] args) {
      new Dog();
}this way you will know what really does happen