HEAR, HEAR!
> Incidentally, I find the worryingly common practice of
> setting all variables to zero / null at the top of a program
> very annoying as it hides the very useful unassigned variable
> trap, leaving you thinking your program works when actually
> it doesn't.
>
> Martin Phillips
> Ladybridge Systems
Yes, this practice HIDES real errors.
I too see it a lot, and I think it is absolutely disgusting.
Maybe the practice originated with programmers who were used to working
in languages where they had to declare variables & var types at the top
of their program. They just felt kinda naked without saying,
I=0;A='';[EMAIL PROTECTED], at the top of their basic code. A poor reason.
Don't do it.
Be aware that the *occasional* such message may hint at a *multitude* of
unreported error incidents. Especially when the error is deep inside an
important loops. Let me illustrate by expanding Martin's example:
LOOP
GOSUB ASSIGN.A
BEGIN CASE
CASE A = 1; B = 'Apple'
CASE A = 2; B = 'Orange'
CASE A = 3; B = 'Banana'
END CASE
DISPLAY B
REPEAT
You will get an "unassigned error" message only if A just happens to not
be 1,2,or 3 on the very FIRST pass through the loop. Subsequent passes
where that occurs would use the value assigned to B on the previous
iteration. UV will be happy to do so.
Initializing B at the top of the program, above the loop, would
eliminate those occasional error message but not eliminate the buggy
code or a fundamental logic flaw.
Try to initialize & assign variables exactly where they apply. Then
watch for error messages that point out your flaws, and be grateful for
them.
Chuck Stevenson
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