[Lazarus] Compare record

[Sven Barth]

On 10.03.2015 22:23, aradeonas wrote:
> Hi,
> How can I compare two record?
> Like this :
>
>     type
>     TRec=record
>     na:string;
>     end;
>
>     var
>     R1,R2:TRec;
>     Begin
>     R1.na:='A';
>     R2.na:='B';
>     if R1<>R2 then
>     Showmessage('Error')

At the declaration of TRec add this:

=== code begin ===

operator = (aLeft, aRight: TRec): Boolean;

=== code end ===

and then implement it like this:

=== code begin ===

operator = (aLeft, aRight: TRec): Boolean;
begin
   Result := aLeft.na = aRight.na;
end;

=== code end ===

Alternatively you can declare the operator inside TRec if you enable 
modeswitch advancedrecords:

=== code begin ===
type
   TRec = record
     na: String;
     class operator = (aLeft, aRight: TRec): Boolean;
   end;

=== code end ===

Implementation:

=== code begin ===

class operator TRec.=(aLeft, aRight: TRec): Boolean;
begin
   Result := aLeft,na = aRight.na;
end;

=== code end ===

This /should/ work though I did not test it by compilation.

Regards,
Sven