From: AppleII717 <salex@...>
Date: 2010-08-18T10:06:15+09:00
Subject: Re: Strange behavior of or condition in loop

On Aug 17, 7:09 pm, Colin Bartlett <colin...@googlemail.com> wrote:
> [Note:  parts of this message were removed to make it a legal post.]
>
> On Wed, Aug 18, 2010 at 12:40 AM, skim <skim...@gmail.com> wrote:
> > and/or aren't the same as &&/||.  they have lower operator precedence than
> > latter.
>
> And to be particular for the OP's problem "and" and "or" have lower
> precedence than "=" assignment. (And have the same precedence as each
> other.) So
>   dirty = dirty or found
> is being parsed as
>   (dirty = dirty) or found
> But since "&&" has a higher precedence than "||" which has a higher
> precedence than "=" assignment, if you replaced the "or" in the unbracketted
> version by "||" you should now get the results of the bracketted version.
> (At least, it worked for me just now.)
>
> skim: Thanks for the link - I mostly use "&&" and "||" (and sometimes also
> parentheses just to be sure and to be explicit) but the explanations of the
> history will probably make it easier for me to remember the precedence of
> "and" and "or" when I see them being used.


Thanks for the reply, explanation and link. I knew they had different
precedence, but I never looked them up but figured they'd be next to
each other. Never crossed my mind that assignment would have a higher
precedence.

A little disappointed in that I was happy to see "and" and "or"
because I never liked the symbol operators. Not so much that they are
bad, but one language uses & and another uses && and "and" just seems
so much clearer.

I hopefully will remember the next time, but may just use parentheses
to keep my mind straight.

Steve Alex