Multidimensional array access

Ali Çehreli via Digitalmars-d-learn digitalmars-d-learn at puremagic.com
Tue Dec 20 12:17:37 PST 2016


On 12/20/2016 11:59 AM, somebody wrote:
> I though D should have syntax similarities with C, but recently I've
> found that array indexing in D is different. Suppose we have a code:
>
> import std.stdio;
>
> void main ()
> {
>     wstring[6][2] strings;
>     strings[2][0] = "test";
> }
>
>
> It fails to compile because of error:
>
> "./main.d(6): Error: array index 2 is out of bounds strings[0 .. 2]"
>
> Why? There should be 6 rows and 2 columns, but it seems that it's the
> opposite. Am I misunderstood something or is it a bug?
>

Yes, opposite.

C's array declaration mimics the way arrays are used in code: first row, 
then column. In D, array declarations are always "type followed by 
square brackets";

     int[N] arr;

Array of arrays follow the same consistent definition: first type, then 
the square brackets. So if we need an array of 6 elements where the type 
of elements is int[2], then we follow that description (space added for 
emphasis):

     int[2] [6] arr;

Ali



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