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

Groups > comp.lang.javascript > #7707

Re: Regular expression question

Followups directed to: comp.lang.javascript

Show all headers | View raw

Lasse Reichstein Nielsen wrote:

> cerr <ron.eggler@gmail.com> writes:
>> First thing, I'm a regular expression newbie.... somewhat anyways...
>> I would like to recognize the difference between this url:
>> http://quaaoutlodge.com/site/the-lodge/our-history.html
>> and that url:
>> http://quaaoutlodge.com/site/the-lodge.html
>> and at the same time extract the document name (our-history or the-
>> lodge) and the directory name if present (the-lodge).
>> I got stuck at how rto rcognize the second directory instead of the
>> first (the-lodge/ instead of site/) with "\b\/[a-z]+\/" how do i get
>> the second one only?
> 
> When you think a RegExp might solve your problem - stop for a moment
> and think whether there is also a simpler solution :)

I cannot think of anything that is simpler than

  var matches = url.match(/(.*)\/([^\/]+)$/);

and then have a look at matches[1] ("directory") and matches[2] ("document 
name").  But that's me.

> In this case, I'd just do:
> 
>   function name(url) {

That is a poor function identifier.

>     var name_end = url.lastIndexOf(".");
>     var name_start = url.lastIndexOf("/", name_end) + 1;

Paths may contain dots.  Resource names do not need to.

>     return url.substr(name_start, name_end);

You meant

  return url.substring(name_start, name_end);

String.prototyp.substr(), OTOH, is proprietary – which is why it should not 
be used – and has ifferent semantics:

| B.2.3 String.prototype.substr (start, length)

>   }
> 
> If your URLs aren't always that simple, you'd need to adapt a RegExp too.

The general solution to this problem is so simple that you really could have 
posted it (BTDT).  OTOH, that is also why the OP could have found it by 
STFW.


PointedEars
-- 
Prototype.js was written by people who don't know javascript for people
who don't know javascript. People who don't know javascript are not
the best source of advice on designing systems that use javascript.
  -- Richard Cornford, cljs, <f806at$ail$1$8300dec7@news.demon.co.uk>

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

Thread

Regular expression question cerr <ron.eggler@gmail.com> - 2011-10-25 21:43 -0700
  Re: Regular expression question Mike Duffy <never@you.mind.com> - 2011-10-26 12:11 +0000
  Re: Regular expression question Denis McMahon <denismfmcmahon@gmail.com> - 2011-10-26 16:54 +0000
  Re: Regular expression question Lasse Reichstein Nielsen <lrn.unread@gmail.com> - 2011-10-26 19:33 +0200
    Re: Regular expression question Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-10-26 23:40 +0200
      Re: Regular expression question Antony Scriven <adscriven@gmail.com> - 2011-10-27 17:30 -0700
        Re: Regular expression question Antony Scriven <adscriven@gmail.com> - 2011-10-27 17:39 -0700
          Re: Regular expression question Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-10-28 03:50 +0200
            Re: Regular expression question Antony Scriven <adscriven@gmail.com> - 2011-10-28 08:46 -0700
            Re: Regular expression question Lasse Reichstein Nielsen <lrn.unread@gmail.com> - 2011-10-28 18:50 +0200
              Re: Regular expression question Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-10-28 19:50 +0200
                Re: Regular expression question Antony Scriven <adscriven@gmail.com> - 2011-10-28 11:41 -0700
                Re: Regular expression question Antony Scriven <adscriven@gmail.com> - 2011-10-28 12:54 -0700
  Re: Regular expression question Dr J R Stockton <reply1143@merlyn.demon.co.uk> - 2011-10-27 19:41 +0100
    Re: Regular expression question Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-10-28 04:12 +0200

csiph-web