Initialise string function result?

Question

I\'ve just been debugging a problem with a function that returns a string that has got me worried. I\'ve always assumed that the implicit Result variable for functions that

Answer 1

Alex's answer is nearly always right and it answers why I was seeing the strange behaviour that I was, but it isn't the whole story.

The following, compiled without optimisation, produces the expected result of sTemp being an empty string. If you swap the function out for the procedure call you get a different result.

There seems to be a different rule for the actual program unit.

Admittedly this is a corner case.

program Project1;

{$APPTYPE CONSOLE}

uses System.SysUtils;

  function PointlessFunction: string;
  begin
  end;

  procedure PointlessProcedure(var AString: string);
  begin
  end;

var
  sTemp: string;
begin
  sTemp := '1234';
  sTemp := PointlessFunction;
  //PointlessProcedure(sTemp);
  WriteLn('Result:' + sTemp);
  ReadLn;
end.