E2025 Procedure cannot have a result type (Delphi)

Go Up to Error and Warning Messages (Delphi)

You have declared a procedure, but given it a result type. Either you really meant to declare a function, or you should delete the result type.

program Produce;

procedure DotProduct(const A,B: array of Double): Double;
var
  I: Integer;
begin
  Result := 0.0;
  for I := 0 to High(A) do
    Result := Result + A[I]*B[I];
end;

const
  C: array [1..3] of Double = (1,2,3);

begin
  Writeln( DotProduct(C,C) );
end.

Here DotProduct was really meant to be a function, we just happened to use the wrong keyword...

program Solve;

function DotProduct(const A,B: array of Double): Double;
var
  I: Integer;
begin
  Result := 0.0;
  for I := 0 to High(A) do
    Result := Result + A[I]*B[I];
end;

const
  C: array [1..3] of Double = (1,2,3);

begin
  Writeln( DotProduct(C,C) );
end.

Just make sure you specify a result type when you declare a function, and no result type when you declare a procedure.