Extend the library class with your own method in Delphi Pascal

StringGridn.rotate(angle);

rotate( StringGridn, angle);

type 
 TStringGridHelper = class helper for TStringGrid
 procedure Rotate(Angle: Single);
 end;

procedure TStringGridHelper.Rotate(Angle: Single);
begin
 {your implementation }
 Rotate (Self, Angle); 
end;

StringGridn.Rotate(Angle);

I want to know if there is a way to add custom methods for existing/included class components in Delphi Pascal.

I want to use it to rotate StringGrid like this :

StringGridn.rotate(angle);

Replace:

rotate(StringGridn, angle );

Thank you for your suggestion:)

You can use the helper in the example below, please refer to Class and Record Helpers ( Delphi).

type 
 TStringGridHelper = class helper for TStringGrid
 procedure Rotate(Angle: Single);
 end;

procedure TStringGridHelper. Rotate(Angle: Single);
begin
 {your implementation }
 Rotate(Self, Angle); 
end;

Then call

StringGridn.Rotate(Angle);