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Re: Good use of bitwise NOT "~" or unnecessary obfuscation?

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On Thu, 01 Nov 2012 18:32:59 -0700, RobG wrote:

>     if (~someString.indexOf('foo'))
>
> Can anyone see issues with the above? Other than perhaps some not seeing
> the bitwise NOT operator "~" so misunderstanding the test?

You're making assumptions about the bitwise representation of -1 and 0 
that might be implementation dependant.

I can't think of any reason why anyone would write a javascript 
implementation where two's complement wasn't used to store integers, but 
unless there's a specification somewhere that mandates two's complement 
for integers, then you're taking a risk based on an assumption about how 
everyone implements integer math that might not always be valid.

Bitfields and integers, although appearing to be the the same, may not 
always behave in the same way. In this case, I'd say that just because in 
every system that you (and I) am familiar with this would be ok, doesn't 
mean that there isn't a platform out there somewhere, now or in the 
future, where it won't work.

Rgds

Denis McMahon

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Good use of bitwise NOT "~" or unnecessary obfuscation? RobG <rgqld@iinet.net.au> - 2012-11-01 18:32 -0700
  Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Denis McMahon <denismfmcmahon@gmail.com> - 2012-11-02 06:14 +0000
    Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Patricia Shanahan <pats@acm.org> - 2012-11-02 02:28 -0700
  Re: Good use of bitwise NOT "~" or unnecessary obfuscation? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2012-11-02 10:22 +0100
    Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Tim Streater <timstreater@greenbee.net> - 2012-11-02 10:37 +0100
    Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Patricia Shanahan <pats@acm.org> - 2012-11-02 06:25 -0700
      Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Asen Bozhilov <asen.bozhilov@gmail.com> - 2012-11-02 06:35 -0700
      Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> - 2012-11-02 14:58 +0100
        Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Patricia Shanahan <pats@acm.org> - 2012-11-02 08:49 -0700
          Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> - 2012-11-04 21:52 +0100
            Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Tim Streater <timstreater@greenbee.net> - 2012-11-04 22:49 +0000
              Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> - 2012-11-05 13:18 +0100
              Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Scott Sauyet <scott.sauyet@gmail.com> - 2012-11-06 06:48 -0800
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Tim Streater <timstreater@greenbee.net> - 2012-11-06 15:04 +0000
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Gene Wirchenko <genew@ocis.net> - 2012-11-06 10:43 -0800
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Scott Sauyet <scott.sauyet@gmail.com> - 2012-11-06 11:22 -0800
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Patricia Shanahan <pats@acm.org> - 2012-11-06 12:16 -0800
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Scott Sauyet <scott.sauyet@gmail.com> - 2012-11-06 12:53 -0800
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> - 2012-11-07 17:34 +0100
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-11-07 23:21 +0100
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2012-11-07 23:23 +0100
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Gene Wirchenko <genew@ocis.net> - 2012-11-07 17:00 -0800
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2012-11-08 07:16 +0100
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Dr J R Stockton <reply1245@merlyn.demon.co.uk.invalid> - 2012-11-07 17:50 +0000
            Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Dr J R Stockton <reply1245@merlyn.demon.co.uk.invalid> - 2012-11-05 19:26 +0000
              Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Stefan Weiss <krewecherl@gmail.com> - 2012-11-07 22:13 +0100
        Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Gene Wirchenko <genew@ocis.net> - 2012-11-02 09:51 -0700
      Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-11-02 18:41 +0100
        Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Patricia Shanahan <pats@acm.org> - 2012-11-02 12:30 -0700
          Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Tim Streater <timstreater@greenbee.net> - 2012-11-02 20:33 +0000
            Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> - 2012-11-04 21:57 +0100
              Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Tim Streater <timstreater@greenbee.net> - 2012-11-04 22:44 +0000
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Andrew Poulos <ap_prog@hotmail.com> - 2012-11-05 15:41 +1100
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Tim Streater <timstreater@greenbee.net> - 2012-11-05 09:07 +0000
          Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-11-02 22:10 +0100
            Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Patricia Shanahan <pats@acm.org> - 2012-11-02 15:22 -0700
              Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-11-03 10:19 +0100
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Patricia Shanahan <pats@acm.org> - 2012-11-03 13:05 -0700
                Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-11-03 21:39 +0100
        Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-11-03 12:26 +0100
  Re: Good use of bitwise NOT "~" or unnecessary obfuscation? "Jukka K. Korpela" <jkorpela@cs.tut.fi> - 2012-11-02 12:28 +0200
    Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Gene Wirchenko <genew@ocis.net> - 2012-11-02 10:00 -0700
  Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Asen Bozhilov <asen.bozhilov@gmail.com> - 2012-11-02 06:15 -0700
  Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Scott Sauyet <scott.sauyet@gmail.com> - 2012-11-06 06:32 -0800
    Re: Good use of bitwise NOT "~" or unnecessary obfuscation? RobG <rgqld@iinet.net.au> - 2012-11-06 18:23 -0800
      Re: Good use of bitwise NOT "~" or unnecessary obfuscation? Scott Sauyet <scott.sauyet@gmail.com> - 2012-11-07 11:22 -0800

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