I don't know what you mean by "assimilable" in this context, but arrays
in Java are a kind of object. In the above code, "a" is reference pointing
to an object of type "int[][]". "a[0]" is an expression which resolves to a
reference pointing to an object of type "int[]". There is no requirement in
Java that objects take up a contiguous region of memory.

   - Oliver

If you built a triangular array in C, using the "natural" representation as an
array of pointers, then it would be quite similar to the above, yes.

Depends.  A rectangular array in C can be constructed in two ways.  One way is
just like the triangular array, where the "main" array contains pointers to
separate arrays for each row (or is it column -- I can never remember ?)   The
other way is that the C compiler will build a single block of memory of size
N*M, and each row/column access will be converted by the compiler into a single
access to the correct cell in that array (using a bit of arithmetic to help).

The second form has the advantage that it doesn't require a double indirection
to get at the data.

If you create a two dimensional array in Java, then you are using the
equivalent of the first form; there is no built-in equivalent to the second.
So if you need the extra performance (which sometimes happens, but not often)
then you have to use a single large array and code up the arithmetic yourself.

   -- chris