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?

On Tuesday, 20 December 2016 at 19:59:41 UTC, 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?

Your code is like this:

alias S = wstring[6];
S[2] strings;
strings[2] = "test";

You see your error now ?

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

Thanks for the explanation