Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.javascript > #18077

Re: ScreenName validation

Show all headers | View raw

Stefan Weiss <krewecherl@gmail.com> writes:

> Could you give an example of when the literal ] character doesn't have
> to be escaped in a character class?

I'm not sure what you are asking. Examples in other languages?

$ php -r 'echo preg_match("/^[]]$/", "]"), "\n";'
1

$ irb
>> /^[]]$/ =~ "]"
(irb):1: warning: character class has `]' without escape
=> 0

$ python
[...]
>>> import re
>>> re.compile('^[]]$').match(']')
<_sre.SRE_Match object at 0x109e39168>

$ groovysh
[...]
groovy:000> "]" ==~ /^[]]$/
===> true

> The empty character class is supported in many (but not all) PCRE-like
> regex implementations.

$ perl -e 'print "]" =~ /^[]]$/, "\n";'
1

> In addition to "\", "]", and "-", some languages also require the regex
> delimiter to be escaped in regex literals.

Well, some languages require you to .NOT escape the underscore. :-)

Back to comp.lang.javascript | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

ScreenName validation "Mel Smith" <med_cutout_syntel@aol.com> - 2013-01-08 10:44 -0700
  Re: ScreenName validation Scott Sauyet <scott.sauyet@gmail.com> - 2013-01-08 11:02 -0800
    Re: ScreenName validation "Mel Smith" <med_cutout_syntel@aol.com> - 2013-01-08 13:05 -0700
    Re: ScreenName validation Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2013-01-11 01:28 +0100
      Re: ScreenName validation Jeff North <jnorthau@yahoo.com.au> - 2013-01-11 12:23 +1100
        Re: ScreenName validation Stefan Weiss <krewecherl@gmail.com> - 2013-01-11 03:38 +0100
        Re: ScreenName validation Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2013-01-11 20:35 +0100
          Re: ScreenName validation Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2013-01-11 21:22 +0100
            Re: ScreenName validation Stefan Weiss <krewecherl@gmail.com> - 2013-01-11 22:09 +0100
              Re: ScreenName validation Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2013-01-11 23:23 +0100
                Re: ScreenName validation Stefan Weiss <krewecherl@gmail.com> - 2013-01-12 00:26 +0100
                Re: ScreenName validation Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2013-01-12 00:54 +0100
              Re: ScreenName validation Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2013-01-12 00:22 +0100
          Re: ScreenName validation Scott Sauyet <scott.sauyet@gmail.com> - 2013-01-11 13:29 -0800
            Re: ScreenName validation Eric Bednarz <bednarz@fahr-zur-hoelle.org> - 2013-01-12 02:31 +0100

csiph-web