[SOLVED] Casting array type

[Dibo]

Hi,

I can't understand casting arrays as method argument. For example, I have this code:

Code: Pascal  [Select][+][-]

1. type
2.   TMyArrayOfString = array of string;
3.  
4.   { TForm1 }
5.  
6.   TForm1 = class(TForm)
7.     Button1: TButton;
8.     procedure Button1Click(Sender: TObject);
9.   private
10.     { private declarations }
11.   public
12.     { public declarations }
13.     procedure Test(S: TMyArrayOfString);
14.   end;
15.  
16. var
17.   Form1: TForm1;
18.  
19. implementation
20.  
21. {$R *.lfm}
22.  
23. { TForm1 }
24.  
25. procedure TForm1.Button1Click(Sender: TObject);
26. const
27.   tmp: array[0..1] of string = ('one', 'two');
28. begin
29.   //Test(['one', 'two']); <-- this doesn't work
30.   Test(tmp);
31. end;
32.  
33. procedure TForm1.Test(S: TMyArrayOfString);
34. begin
35.  
36. end;  
37.  

Why I can't just call Test(['one', 'two'])? If I call this I get error:

unit1.pas(38,22) Error: Incompatible type for arg no. 1: Got "Array Of Const/Constant Open Array of Constant String", expected "TArrayOfString"

I must declare temporary constant (which is array of string too) and then send it as argument. If argument is type "array of string" instead of TMyArrayOfString then is ok. Why compilator is so sensitive in this case?

Regards

[Zoran]

There is always confusion with open array parameters and dynamic arrays. These two are different things, but the syntax for declaring these looks same.

Take a look at this article: http://rvelthuis.de/articles/articles-openarr.html
In this article find a paragraph named "Confusion".

[Dibo]

Great article! Thanks