just for fun2 - for the uninitiated

[Anshuman Acharya]

this compiles:
//code
class a{
public static void main(String args[]){
Runnable r = (Runnable) (new a());
//String[] s = (String[])(new a()); this stat. doesn't compile
}}
//code ends
try putting final before class a and see.

[natarajan meghanathan]

A non-final class can be cast to an interface and vice-versa. (RHE Pg. 117).
A reference of Object only can be cast to an array (again RHE Pg.117).

[Anshuman Acharya]

sorry, nat!
for an object array, even it's superclass' arrayis allowed to refer it...
primitive arrays can be cast to themselves, Object or Cloneable.