two Object[] into one

[RVic]

If I have Object array1[] and Object array2[] , how can I make Object
array3[] without copying over each element from each array into
array3 ? Thanks.

 

[Simon]

If I have Object array1[] and Object array2[] , how can I make Object

array3[] without copying over each element from each array into
array3 ? Thanks.

With arrays, this is impossible. Note, however, that in Java, you are
only copying references, which is relatively cheap. System.arraycopy()
does this for you.

If that does not suit your needs, think about implementing something
like a Union data structure inheriting from Collection or List which is
a view of two underlying lists, Collections, or arrays.

Cheers,
Simon

 

[Arne Vajhøj]

If I have Object array1[] and Object array2[] , how can I make Object
array3[] without copying over each element from each array into
array3 ? Thanks.

If you want array3 to contains all elements from both array1 and
array2, then that requires moving data, because arrays are
stored sequentially in Java.

You can easily make array3 an array that has two elements
array1 and array2.

Arne

 

[Roedy Green]

If I have Object array1[] and Object array2[] , how can I make Object
array3[] without copying over each element from each array into
array3 ? Thanks.

The closest thing you could do is this:

array[][] array3 = new Object[2];
array3[0] = array1;
arry3[1] = array2;

But if you modify array3, you will also be modifying array1 or array2
since there is only one copy of the array1/array2 references.

Single dimensioned arrays are always contiguous in ram, so to get an
array3[] you are going to need to copy elements.
--
Roedy Green Canadian Mind Products
http://mindprod.com

"Let us pray it is not so, or if it is, that it will not become widely known."
~ Wife of the Bishop of Exeter on hearing of Darwin's theory of the common descent of humans and apes.

 

[Daniel Pitts]

If I have Object array1[] and Object array2[] , how can I make Object
array3[] without copying over each element from each array into
array3 ? Thanks.

Magic or luck, but not any other way.

 

[Arne Vajhøj]

If I have Object array1[] and Object array2[] , how can I make Object
array3[] without copying over each element from each array into
array3 ? Thanks.

simple task

Object[] array3 = new Object[0];

no need to copy over anything..

Make a guess about what the original poster wanted.

Arne

 

[Roedy Green]

I wouldn't have written "scnr" if I didn't guess that this was not what
the Op wanted.

see http://mindprod.com/jgloss/scnr.html
--
Roedy Green Canadian Mind Products
http://mindprod.com

"Let us pray it is not so, or if it is, that it will not become widely known."
~ Wife of the Bishop of Exeter on hearing of Darwin's theory of the common descent of humans and apes.

 

[Lew]

see <http://mindprod.com/jgloss/scnr.html>

Man, am I ever glad for that link. Christian completely lost me with
that obscure abbreviation. I thought it was a signature, like his
initials, or something. Thanks, Roedy.

If I had understood "leetsprech" or whatever execration "scnr"
represents, I would have been LMFAOOL, no doubt.

BTW, even without the explicit hint that his comment was intended for
humor, Christian's suggestion communicated dry wit. The content
provided the context.