How can a Collection of Primitive type be a Reference Type ?

Question

Here's the example that i am running:
public class one
     public static void main(String args[])
          int i[] = new int[]{0,1,2,3,4,5};
          int j[] = i;
          j[0]=100;
          System.out.println(i[0]);
}Output:100
So the question is quite a weird one actually which i haven't seen any book explain...
How can a group of int be a reference type ??
please explain.

Answer 1

i and j are both references. They point to objects. In this case, they point to the same object--an array of int.
The fact that the contained elemets are primitives doesn't change the fact that the container is an object. It's just like if you did
class Foo {
  int i1;
  int i2;
  int i3;
}A Foo object is still an object, even though its member variables are all primitives, and Foo foo; is still a reference variable that points to a Foo object, just as i and j are reference variables that point to array objects.