RE: Operation Precedence questions

[Gord Royle <GRoyle@xxxxxxxx>]

After you've done this for ??? years, you learn the hard way. After you've
worked with 10 or 20 different compilers, you learn not to trust the
compiler either.

Gord

-----Original Message-----
From: Jeff Crosby [mailto:jlcrosby@xxxxxxxxxxxxxxxx]
Sent: Thursday, March 20, 2003 3:56 PM
To: RPG programming on the AS400 / iSeries
Subject: Re: Operation Precedence questions


Gord Royle wrote:

> Take it from someone who went Ga-Ga in School over Boolean Math -
> Parentheses change everything. Try A and B or C and D versus (A and B) or
(C
> and D). Stuff in Parenthesis is always evaluated first. I tend to use lots
> of them 'cause I'm still confused by AND/OR precidence and get even more
> confused when you throw in a NOT. Consider A or B and C or NOT D. <Hair
> starts to come out>.

I'm with you.  I almost always put parentheses in.  In fact, the only 
time I don't put parentheses is when there is only a single condition 
type, i.e.,

                A and B and C
                A or B or C

as soon as there is a mix, I paren it to death like this

                A and (B or C)
                (A and B) or C

I don't even try to remember what operator is evaluated first.  Same 
with numeric expressions.  I _never_ leave it to my memory.             
                
-- 
Jeff Crosby
Dilgard Frozen Foods, Inc.
P.O. Box 13369
Ft. Wayne, IN 46868-3369
260-422-7531

The opinions expressed are my own and not necessarily
the opinion of my company.  Unless I say so.



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