Re: "Condition is Always False" Question

From:

"peter koch" <peter.koch.larsen@gmail.com>

Newsgroups:

comp.lang.c++

Date:

12 Feb 2007 06:36:27 -0800

Message-ID:

<1171290987.763209.266290@v45g2000cwv.googlegroups.com>

On Feb 12, 3:29 pm, Andre Kostur <nntps...@kostur.net> wrote:

"Brian" <bwilk...@gmail.com> wrote in news:1171290076.470125.49620
@q2g2000cwa.googlegroups.com:

I am using Borland C++ Builder 5 for my application. When I build my
application, it states that I have several if-statements that will
always be false. The statements appear correct, so could someone
please enlighten me as to how C++ Builder may think that the
conditions will always be false. See below. Thanks.

<snip>
td.expMon = trk2[9] * 10 + trk2[10];

    // Borland says this is always false, though the condition is
fine.
    if ((td.expMon < 0) || (td.expMon > 12)) {
        err = TKT_INVALID_MONTH;
    }

[snips]

We're not mind-readers.... you haven't told us what the types of expMon,
expDay, or eftwDay are. But my first guess would be that they are all
of some sort of unsigned type, thus all of your "< 0" comparisions will
always be false.

I might have a blind spot here, but this would still leave the other
part of the condition, e.g. (td.expMon > 12) above.
Ahhh... perhaps the compiler complains about part of a boolean
expression? That would make sense (sort of).

/Peter