[fpc-pascal]Re: How to make a constructor failed?

[Yet Another Geek]

program createif;
{$MODE OBJFPC}

uses sysutils;

type TMyClass = class(TObject)
  private
    fFileName:string;
  public
    constructor Create(FN:string; dummy:byte);
    class function Create(FN:string):TMyClass;
end;

constructor TMyClass.Create(FN:string; dummy:byte);
begin
  inherited Create;
  fFileName:=FN;
end;

class function TMyClass.Create(FN:string):TMyClass;
begin
  if FileExists(FN) 
  then Result:=TMyClass.Create(FN, 0)
  else Result:=nil;
end;


var 
  myclass:TMyClass;

begin
  myclass:=TMyClass.Create('aaaa.txt');
  if myclass=nil then begin
    writeln('object not created - file not found');
    exit;
  end else begin
    writeln('Sucess!!!');
    myclass.Free;
  end;
end.


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