Subject:
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Re: Semicolon (;) Confusion
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Newsgroups:
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lugnet.robotics
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Date:
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Fri, 27 Oct 2000 21:28:54 GMT
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Viewed:
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817 times
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John, Thanks for that answer. That same question has haunted me for some
time.
--
Bob Fay
rfay@we.mediaone.net
The Shop
http://www.geocities.com/Heartland/Bluffs/7900/
"John A. Tamplin" <lego-robotics@crynwr.com> wrote in message
news:Pine.A32.3.91.1001027130949.16770f-100000@cyclone.liveonthenet.com...
> On Fri, 27 Oct 2000, Jerry Kalpin wrote:
>
> > In some cases Mark Overmars great RCX Command Center does not flag syntax
> > errors for incorrect use of an ending semicolon, as in the example below.
> > Could someone please explain how semicolons work in NQC? Perhaps there is a
> > good reason for *not* flagging syntax errors in those cases.
> >
> > //a flasher program
> > task main()
> > {
> > SetSensor(SENSOR_1,SENSOR_TOUCH);
> > while (true) // A semicolon here disables program
> > {
> > if (SENSOR_1 == 1) //a semicolon here runs the flasher all the time
> > {
> > On (OUT_B);
> > Wait (10);
> > Off (OUT_B);
> > Wait (100);
> > }
> > }
> > }
>
> NQC implements a syntax similar to C. In C, while and if statements have
> a single statement that is executed if the condition is true. A null
> statement is a valid statement, and a block of statements enclosed in {}
> can be substituted or a statement. So, if you add a semicolon after the
> while:
>
> while(true);
> {
> ...
> }
>
> You have a valid statement that loops continuously doing nothing. The
> rest of the program is never reached. Likewise, if you put it after the
> if, the null statement is executed if the condition is true, and then the
> following block of statements is unconditionally executed.
>
> John A. Tamplin LiveOnTheNet.COM, Inc.
> jat@LiveOnTheNet.COM 2104 West Ferry Way
> 256/705-7007 - FAX 256/705-7100 Huntsville, AL 35801
>
>
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Message is in Reply To:
| | Re: Semicolon (;) Confusion
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| (...) NQC implements a syntax similar to C. In C, while and if statements have a single statement that is executed if the condition is true. A null statement is a valid statement, and a block of statements enclosed in {} can be substituted or a (...) (24 years ago, 27-Oct-00, to lugnet.robotics)
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