Quicker way to cast array items?

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Paul Chapman - 20 Feb 2005 11:16 GMT

I have

Object[] array;

I happen to know that each of the items of the array has class MyClass. I
realize that I can't cast the whole array thus:

(MyClass[]) array

But is there a quicker way than copying the whole array into a new
MyClass[], casting the items one at a time?

TIA.

Cheers, Paul

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Anthony Borla - 20 Feb 2005 12:00 GMT

> I have
>
[quoted text clipped - 7 lines]
> But is there a quicker way than copying the whole array
> into a new MyClass[], casting the items one at a time?

Use:

Object[] srcArray =
new MyClass[]{null, null, null, null};

MyClass[] targetArray =
new MyClass[srcArray.length];

System.arraycopy(srcArray, 0, targetArray, 0,
srcArray.length);

I hope this helps.

Anthony Borla

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Paul Chapman - 20 Feb 2005 13:17 GMT

Anthony,

> Object[] srcArray =
> new MyClass[]{null, null, null, null};
[quoted text clipped - 4 lines]
> System.arraycopy(srcArray, 0, targetArray, 0,
> srcArray.length);

Not quite copy-free, but better than a for-loop. And it worked. Thanks.

Cheers, Paul

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Aleksander =?iso-8859-2?Q?Str=B1czek?= - 20 Feb 2005 13:32 GMT

> Anthony,
>> Object[] srcArray =
[quoted text clipped - 7 lines]
>
> Not quite copy-free, but better than a for-loop. And it worked. Thanks.

If you have srcArray
    Object[] srcArray =
        new MyClass[]{null, null, null, null};
you can just cast it:
    MyClass[] targetArray = (MyClass[]) srcArray;

Copying is required if srcArray is created like tihs:
    Object[] srcArray = new Object[]{null};

Signature

Regards, Olek

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Anthony Borla - 21 Feb 2005 02:19 GMT

> Anthony,
>
[quoted text clipped - 8 lines]
>
> Not quite copy-free, but better than a for-loop.

Indeed, I should think *very significantly better* than a 'for' loop ;) !

> And it worked. Thanks.

More than glad to help get the job done :) !

Cheers,

Anthony Borla

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Quicker way to cast array items?

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