[Lazarus] Testing Assigned object

Hans-Peter Diettrich DrDiettrich1 at aol.com
Mon Apr 25 10:15:57 CEST 2011


SteveG schrieb:
> Is there a simple way to tell if slTest has been assigned in the 
> following ?
> 
> (without specifically assigning it to NIL in the declaration)
> 
> var
>   slTest     :TStringList;
> 
> begin
>   if Assigned(slTest) then FreeAndNil(slTest); // gives exception
> end;

When slTest is a local variable, you should initialize it to Nil. 
Otherwise the variable contains garbage, that most probably is *not* 
Nil, so that FreeAndNil tries to free something that never has been created.

DoDi





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