[fpc-pascal] Re: Runtime error 217 on array of Variant

[Xiangrong Fang]

I found the problem myself.  You have to add "uses Variants" to eliminate
the problem.  So now my questions are:

1) why the Variants unit is required? What does it do?

2) is there any performance penalty using Variant than TVarRec?

Thanks!



2013/9/5 Xiangrong Fang <xrfang at gmail.com>

> Hi there,
>
> I would like to use TVarRec as Variants, after some googling I found this:
>
>
> http://stackoverflow.com/questions/3733640/how-to-convert-between-tvarrec-and-variant
>
> However, it generated Runtime error 217.  My original code (runs OK) is:
>
>   1 program test;
>   2 {$mode objfpc}{$H+}
>   3 procedure vart(par: array of const);
>   4 var
>   5   i: Integer;
>   6 begin
>   7   i := par[0].VInteger;
>   8   WriteLn('first param=', i);
>   9 end;
>  10 begin
>  11   vart([1, 2, 3]);
>  12 end.
>
> Modified code (runtime error 217) is:
>
>   1 program test;
>   2 {$mode objfpc}{$H+}
>   3 procedure vart(par: array of Variant);
>   4 var
>   5   i: Integer;
>   6 begin
>   7   i := par[0];
>   8   WriteLn('first param=', i);
>   9 end;
>  10 begin
>  11   vart([1, 2, 3]);
>  12 end.
>
> Any ideas? Thanks!
>
>
>
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