Array Declaration

[Ram Han]

Object oa = new boolean[20];

I thought above line should give a compiler error.

But it compiled fine, how ?

[Henry Wong]

An array is an object. If you like, you can later cast the "oa" object back to a boolean array, and access it.

Henry

[vipul patel]

A very good explanation of this situation can be found from Khalid Mughal.

Look at this hirachy.

Object
|
Object[], int[], char[],boolean[]
|
Foo[]



So any array of primitives is an object and subclass of GodFather java.lang.Object.

Any array of references is an object and subclass of Object[] which is again an object and subclass of Object.

So all following declarations are legal.

Object o = new int[10];
Object o2 = new char[10];
Object o3 = new boolean[10];
Object o1[] = new Foo[10];
o = o1;

I hope it is clear now.

[Vlado Zajac]

Originally posted by dilip agheda:

Any array of references is an object and subclass of Object[] which is again an object and subclass of Object.

(Direct) superclass of any array is Object. Object[] is supertype of any reference array type, but not superclass of it.

(JLS - Class objects for arrays)
[ December 22, 2005: Message edited by: Vlado Zajac ]