November 9, 2007
Handbook Note 37/113: Assigning Result
Note 37 of 113 of Delphi 2007 Handbook
Note 37: You can write the code also with the classic if-then-else statement, rather then using the initial assignment to the Result:
if ItemIndex >= 0 then
Result := Items [ItemIndex]
else
Result := '';
I tend to prefer setting uninitialized stack values, including local variables and results, even when it is not strictly required, because failing to do so at times results in hard-to-track errors.
To make the note understandable, here is the actual code in the book. Which style do you prefer?
Result := '';
if ItemIndex >= 0 then
Result := Items [ItemIndex];
This blog post is part of my "113 Delphi 2007 Handbook Notes" blogging project, to promote my new Delphi book.
3 Comments
Handbook Note 37/113 Assigning Result
> Which style do you prefer? That depends on if I want speed or less typing.Comment by Andreas Hausladen [] on November 9, 21:50
Handbook Note 37/113 Assigning Result
I prefer the if/then/else version for the fact that
it'll be faster (by a tiny, miniscule fraction of a
nanosecond :-)), since you'll only assign a value to
result once and not (perhaps) twice.
But in other cases (more advanced than the example) I
also use a pre-initialization of Result.
I even use Result in FOR/IN statements, like the
following:
FUNCTION IndexOf(CONST ARR : TArray ; CONST STR :
ShortString) : TRecord;
BEGIN
FOR Result IN ARR DO IF Result.Name=STR THEN EXIT;
Result:=NIL
END;
Comment by Keld R. Hansen
[http://www.heartware.dk]
on November 10, 18:26
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Handbook Note 37/113 Assigning Result
Comment by Benji [] on November 9, 21:12