DllStructCreate string array

[martin]

Should it be possible to create a struct like this?

DllStructCreate("char[40][2]")

which I would expect to be the same as

DllStructCreate("char[40];char[40]")

Here is a script which shows it doesn't work, but maybe I'm doing something wrong.

$d1 = DllStructCreate("char[40];char[40]")
DllStructSetData($d1,1,"first string")
DllStructSetData($d1,2,"second string")

$d2 = DllStructCreate("char[40][2]")
DllStructSetData($d2,1,"apples are fruit",1)
DllStructSetData($d2,1,"oranges are fruit",2)


;this works
$s1 = DllStructGetData($d1,1)
$s2 = DllStructGetData($d1,2)
MsgBox(0,$s1,$s2)

;this doesn't
$s1 = DllStructGetData($d2,1,1)
$s2 = DllStructGetData($d2,1,2)
MsgBox(0,$s1,$s2)

[SmOke_N]

I would think that char[40][2] would be like 40 elements at 2 bytes each.

Edit:

I also don't see an option for multi dimensions ?

Edited September 10, 2007 by SmOke_N

[Siao]

I think the problem in such array char[40][2] is that each of 80 elements still has a length of 1 byte (char).

Edited September 10, 2007 by Siao

[seandisanti]

I think the problem in such array char[40][2] is that each element still has a length of 1 byte (char).

yeah it looks like it's most likely a combination of the wrong data type being used, as you and smoke said, and i'm not sure that you can call dllstructcreate() with a multidimensional array as an argument...

[The Kandie Man]

You can't create multidimensional char arrays. A char is an array of numbers where each element of the array contains the integer decimal ASCII code for each character in the string. That is what a string is in lower level languages, an array of ASCII codes. Therefore, you can't create a multidimensional array like that.

- The Kandie Man ;-)

[martin]

I would think that char[40][2] would be like 40 elements at 2 bytes each.

I wondered that myself and so I tried "char[2][40]" but it didn't help.

I also don't see an option for multi dimensions ?

I think that is the problem, multidimensional arrays just aren't designed into dllstruct. I just hoped that since you can have an array of ints or ptrs, then maybe an array of strings. I suppose that what you would normally do is to have an array of strings and then have a pointer to the array, but how do you do that in AutoIt?

It's a pity because if I want 100 strings each up to 39 characters I have to create a string with "char[40];char[40]... " 100 times instead of "char[40][100], but it's no big deal.

[martin]

You can't create multidimensional char arrays. A char is an array of numbers where each element of the array contains the integer decimal ASCII code for each character in the string. That is what a string is in lower level languages, an array of ASCII codes. Therefore, you can't create a multidimensional array like that.

- The Kandie Man ;-)

When you say a char is an array of numbers you mean a string is an array of numbers. (Or maybe you mean a char array)

Just because of that it doesn't mean you can't have a multidimensional char arrays. In C for example, which treats strings as character arrays, you can have declarations like char testarray[40][100] and that will work fine. You can use testarray[0] or testarray[12] as separate strings.

If you couldn't create a multidimensional array because each element is a number then you couldn't have multidimensional arrays for anything!

If the dllstruct was designed to cope with arrays of strings then there would be no reason not to have char[40][100] and then reference each set of 40 characters as you do for integer arrays with the element and the index. The reason it doesn't work, I assume, is because it's not designed in to work, and not because you can't have multidimensional character arrays.

[SmOke_N]

I wondered that myself and so I tried "char[2][40]" but it didn't help.

I think that is the problem, multidimensional arrays just aren't designed into dllstruct. I just hoped that since you can have an array of ints or ptrs, then maybe an array of strings. I suppose that what you would normally do is to have an array of strings and then have a pointer to the array, but how do you do that in AutoIt?

It's a pity because if I want 100 strings each up to 39 characters I have to create a string with "char[40];char[40]... " 100 times instead of "char[40][100], but it's no big deal.

After reading this, and posting, I played with that very idea... I got no where with it though.

[martin]

After reading this, and posting, I played with that very idea... I got no where with it though.

Thanks for trying SmOke_N.

I suppose it's a question for the developers.