Adding hyphens and underscore to my JS expression test

[Astra]

Hi All

Could somebody please confirm that if I change my JS expression test from:

if (!(/^[a-zA-Z0-9]*$/.test(document. form1.fred.valu e)))

to

if (!(/^[a-zA-Z0-9-_]*$/.test(document. form1.fred.valu e)))

(in other words I've added the hyphen and underscore after the 9)

then I'm allowing the hyphen and underscore as valid chars like a-z 0-9, but
nothing else.

It appears to work, but I don't know if I've screwed up the whole test
rather just the chars I want to add.

Rgds

Robbie

[Dr John Stockton]

JRS: In article <op************ ***@greywyvern. belkin>, dated Tue, 20
Dec 2005 14:11:52 local, seen in news:comp.lang. javascript, GreyWyvern
<sp**@greywyver n.com> posted :

Please stop crossposting over top-level hierarchies without
Followup-To.

Who are you? The deity of Usenet? This thread holds relevance to both
groups, and I believe individuals from both groups are taking part.

He is a reincarnation of Mussolini, with ideas above his station.

--
© John Stockton, Surrey, UK. ?@merlyn.demon. co.uk Turnpike v4.00 MIME ©
Web <URL:http://www.uwasa.fi/~ts/http/tsfaq.html> -> Timo Salmi: Usenet Q&A.
Web <URL:http://www.merlyn.demo n.co.uk/news-use.htm> : about usage of News.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

[Thomas 'PointedEars' Lahn]

Randy Webb wrote:

Thomas 'PointedEars' Lahn said the following on 12/20/2005 3:41 PM:

Wikipedia (<URL:http://en.wikipedia.or g/wiki/JavaScript>) also had
some links to authoring guides and reference material already, which
I updated this morning.

If you are updating Wikipedia then it is even more evidence that it
lacks credibility and you need more/better resources/references.

<URL:http://www.nature.com/news/2005/051212/full/438900a.html>

But it is not possible to satisfy a born ignorant like you.
PointedEars

[GreyWyvern]

And lo, Thomas 'PointedEars' Lahn didst speak in comp.lang.javas cript:

GreyWyvern wrote:

However, it *always* becomes a plain hyphen in square brackets when
escaped.

Yes, but that is not what you stated.

For the benefit of those who don't have a good grasp of regular
expressions (which is a *lot* of people) it is good to reinforce good
composition technique. Despite exceptions and shortcuts, one of these
techniques is to ensure plain hyphens are escaped within square brackets;
this way one can always be sure of their function.

The methods you espouse are merely syntactic sugar.

Which is why I said it is good practice to assume that if it is
unescaped, it could be interpreted in a way which you don't expect.

Good practice is defined by the overall knowledge of participants,
and coders should have a minimum clue about coding. It is clearly
defined where an unescaped hyphen becomes special and where not.

Oh? And you would take the time to describe all these exceptions and
definitions to someone who's having trouble with regular expressions?

I'll admit, the way I originally phrased my answer was false, however, I
cheerfully corrected myself. Thank you for pointing it out.

Please stop crossposting over top-level hierarchies without
Followup-To.

Who are you? The deity of Usenet?

Who are you, ignoring Netiquette?

It is awfully rude to keep setting the F'up-to to a group which is not
read by the individuals you are debating with.

This thread holds relevance to both groups, and I believe individuals
from both groups are taking part.

That is no valid argument. Crossposting over top-level hierarchies, and
into the Big Eight from the outside is evil[tm] in the first place.

Who says? You and your holier-than-thou secret comp-heirarchy society?
Most folks who live in the comp groups are nice regular people who are
happy to help out in the alt groups but prefer a narrower focus. I
sincerely hope you don't think you represent them. I should think they
would be insulted.

Grey

--
The technical axiom that nothing is impossible sinisterly implies the
pitfall corollary that nothing is ridiculous.
- http://www.greywyvern.com/orca#sear - Orca Search - PHP/MySQL site
search engine

[GreyWyvern]

And lo, Thomas 'PointedEars' Lahn didst speak in alt.www.webmaster:

William Tasso wrote:

Thomas 'PointedEars' Lahn <Po*********@we b.de> said:

If alt.ALL were properly organized, a group like
alt.www.webmaster would not even exist because there
already is comp.infosystem s.www.authoring.ALL.

An interesting idea, however groups in the ciwa sub-hierarchy are fairly
narrow in focus - that's not a criticism, it's just the way it is.

You could not be more wrong.

I don't think you understand what William means by "narrow in focus".

Those that prefer that type of structure will eventually find their way
over there.

The last time I checked on my news server (about a minute ago), there are

[snip: bunchacompgroup s]

All of which are *individually* much more narrow in focus than the groups
under alt.www. Like William says, this is not criticism nor is it an
insult of any kind, it is the way things are. Often a narrower focus is
just what one is looking for; for others, it is sufficient to know a
little about many topics.

If this offends you somehow... well, let's just say you need to relax.

Grey

--
The technical axiom that nothing is impossible sinisterly implies the
pitfall corollary that nothing is ridiculous.
- http://www.greywyvern.com/orca#sear - Orca Search - PHP/MySQL site
search engine

[Randy Webb]

Thomas 'PointedEars' Lahn said the following on 12/20/2005 7:32 PM:

Randy Webb wrote:

Thomas 'PointedEars' Lahn said the following on 12/20/2005 3:41 PM:

Wikipedia (<URL:http://en.wikipedia.or g/wiki/JavaScript>) also had
some links to authoring guides and reference material already, which
I updated this morning.

If you are updating Wikipedia then it is even more evidence that it
lacks credibility and you need more/better resources/references.

<URL:http://www.nature.com/news/2005/051212/full/438900a.html>

But it is not possible to satisfy a born ignorant like you.

I have told you already, repeatedly, that if you do not understand the
language and it's dialects then you shouldn't endeavor in trying to
understand anything written in it.

But for the sake of posterity, let me explain what I said in a way that
you may understand it:

A reference (in this case Wikopedia) is only as good as its contributors.
Considering that all you have to do to be a contributor to Wikipedia is
to have an Internet Connection, the ability to click the "Edit this
Page" link at the top, Edit it and Save it, then the realm of
contributors is practically unlimited.

I edited the Javascript section you provided the URL to while typing
this response. If I don't forget, I will change it back tomorrow. Or,
can you tell me what I changed?

The sheer coverage of contributors and that the paragraph on Whitespace
has several inaccuracies and mis-leading conclusions, then the
indication has to be that it's not a very resource when it comes to
JavaScript and JScript.
If you took that personal then you have a problem.

Now, if you want to continue this in an educated civilized manner, fine.
If you want to make it personal, that is fine also.

--
Randy
comp.lang.javas cript FAQ - http://jibbering.com/faq & newsgroup weekly
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/

[Jasen Betts]

["Followup-To:" header set to comp.lang.javas cript.]
On 2005-12-20, GreyWyvern <sp**@greywyver n.com> wrote:

And lo, Astra didst speak in alt.www.webmaster,comp.lang.javascript:

Hi All

Could somebody please confirm that if I change my JS expression test
from:

if (!(/^[a-zA-Z0-9]*$/.test(document. form1.fred.valu e)))

to

if (!(/^[a-zA-Z0-9-_]*$/.test(document. form1.fred.valu e)))

(in other words I've added the hyphen and underscore after the 9)

then I'm allowing the hyphen and underscore as valid chars like a-z 0-9,
but nothing else.

It appears to work, but I don't know if I've screwed up the whole test
rather just the chars I want to add.
The hyphen character is *always* a special character within square
brackets in regular expressions.

You'll need to escape it with a
backslash.

if (!(/^[a-zA-Z0-9\-_]*$/.test(document. form1.fred.valu e))) ???

is this unique to javascript regular expressions.

in ordinary (posix 1003.2) REs
- is non special at either end of a brasked expression and
\ is always literal inside brackets.
It is important to note that outside of square brackets, the hyphen has
*no* special meaning and can be left unescaped.

it seems that in javascript RE bracket expression - is literal at the
end of the expression or if escaped and \ must be doubled to be literal.
Bye.
Jasen

[Lasse Reichstein Nielsen]

Randy Webb <Hi************ @aol.com> writes:

I edited the Javascript section you provided the URL to while typing
this response. If I don't forget, I will change it back tomorrow. Or,
can you tell me what I changed?

That's easy! You made "object-based" on line 1 no longer be a Wiki-link.

I could change it back, but I'll let you do it.

/L 'compare NNTP-posting-host to history :P'
--
Lasse Reichstein Nielsen - lr*@hotpop.com
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleD OM.html>
'Faith without judgement merely degrades the spirit divine.'

[GreyWyvern]

And lo, Jasen Betts didst speak in comp.lang.javas cript:

On 2005-12-20, GreyWyvern <sp**@greywyver n.com> wrote:

You'll need to escape it with a
backslash.

if (!(/^[a-zA-Z0-9\-_]*$/.test(document. form1.fred.valu e)))

???

is this unique to javascript regular expressions.

in ordinary (posix 1003.2) REs
- is non special at either end of a brasked expression and
\ is always literal inside brackets.

Javascript uses Perl compatible regular expressions.

It is important to note that outside of square brackets, the hyphen has
*no* special meaning and can be left unescaped.

it seems that in javascript RE bracket expression - is literal at the
end of the expression or if escaped and \ must be doubled to be literal.

Exactly :) However, since a plain - can be special OR literal within
square brackets depending on where it is placed, it is good form always to
escape it. This way you are *sure* it is being taken as a literal, and is
a big help for those who may edit your expressions later, or if you build
your expressions dynamically.

Please stop setting the followup; it is quite rude. Interested parties
from both x-posted groups are participating in this thread.

Grey

--
The technical axiom that nothing is impossible sinisterly implies the
pitfall corollary that nothing is ridiculous.
- http://www.greywyvern.com/orca#sear - Orca Search - PHP/MySQL site
search engine

[VK]

<offtopic>
Lasse Reichstein Nielsen wrote:

DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleD OM.html>

FYI:
Death colors do not work on FF 1.5 Final - just an empty black canvas
is displayed.
It still works on the latest Opera 8.51

</offtopic>

[VK]

VK wrote:

<offtopic>
Lasse Reichstein Nielsen wrote:

DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleD OM.html>

FYI:
Death colors do not work on FF 1.5 Final - just an empty black canvas
is displayed.
It still works on the latest Opera 8.51

</offtopic>

It works again. What was the trick?