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Re: behavior of || operator

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Mark wrote:
) if ((action != ATTACH) || (action != DETACH))
)     puts("invalid action");

It looks like you don't understand De Morgan's laws.

In English:
If action is not attach or action is not detach, then it is an invalid
action.

What you wanted to do is this:
If action is not attach or detach, then it is an invalid action.

Which is:
 if (!(action == ATTACH || action == DETACH))
     puts("invalid action");

Which, according to De Morgan, is equivalent to:
 if ((action != ATTACH) && (action != DETACH))
     puts("invalid action");


SaSW, Willem
-- 
Disclaimer: I am in no way responsible for any of the statements
            made in the above text. For all I know I might be
            drugged or something..
            No I'm not paranoid. You all think I'm paranoid, don't you !
#EOT

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behavior of || operator "Mark" <mark_cruzNOTFORSPAM@hotmail.com> - 2011-10-07 13:13 -0400
  Re: behavior of || operator James Kuyper <jameskuyper@verizon.net> - 2011-10-07 14:11 -0400
  Re: behavior of || operator John Gordon <gordon@panix.com> - 2011-10-07 18:47 +0000
  Re: behavior of || operator Willem <willem@toad.stack.nl> - 2011-10-07 19:50 +0000
  Re: behavior of || operator Gene <gene.ressler@gmail.com> - 2011-10-08 13:58 -0700

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