Why can you cast int[] to Object, but not to Object[]?

Question

So this works:

int i;
Object a  = (Object) i;
int[] t;
Object b = (Object) t;
String[] s;
Object[] t = (Object[]) s;

But this does not:

int[] t;
Object[] z = (Object[]) t;

All in all I get the first part (boxing), but I find it highly unintuitive that the second part does not work. Is there a specific reason why (beside String inheriting from Object and int not inheriting from Object)?

Edit:

To refine my question, this also works:

int a = 2;
int b = 3;
int c = 4;
int d = 2;
Object[] o = new Object[] {a,b,c,d};

But then the following does not:

int[] t = (int[]) o;

Surprisingly you get the same problem with String:

String sa = "a";
String sb = "b";
String sc = "c";
String sd = "d";
Object[] so = new Object[] {sa,sb,sc,sd};
String[] st = (String[]) so;

Yields a class cast exception on the last line. Still this works:

Object[] sy = (Object[])new String[]{sa,sb,sc,sd};
String[] sz = (String[]) sy;

Answer 1

A int[] is an array of primitives but also an Object itself. It is not an array of Objects

There is no auto-boxing support for arrays. You need to pick the right type of array to start with and not be converting it at runtime.