Hi Peter, I wasn't really asking a question so much as noting down a useful observation I'd made.
As you can see from my examples, it's not just the matches from the global RegExp that I'm after, it's also the sub patterns. These are never returned by anything when using a global RegExp. My message was just about a technique which actually uses .replace with a callback rather than .match as a way of getting everything about each capture (including lastIndex, and all the sub patterns). Just thought it might help somebody else. Pete On 23 Oct 2011, at 10:01, Peter van der Zee wrote: > On Sun, Oct 23, 2011 at 10:41 AM, pete otaqui <[email protected]> wrote: >> Regular Expressions in Javascript don't make it easy to capture sub patterns >> when operating globally (i.e. using the 'g' modifier). >> > snip... >> >> So are we stuck? Do we need to use two separate string manipulation >> routines? No: we can use "replace" with a callback (and not do any actual >> replacing). Consider the following: > snip... >> >> We don't need to return anything from the callback, since neither are we >> assigning the return from string.replace to anything - but this is the only >> apparent method of looping through a global regexp with sub patterns. > > Ok, I hope I'm reading your mail/question properly, but I think you're > trying to get all matches of a global regexp. If so, good news! It can > be done. If not, well, then please clarify your actual question or > hope somebody else does get it ;) > > So regexp objects have this property called `lastIndex`. It's > basically only useful for global regexes, but will exist nonetheless. > The beauty about this property is that it's actually taken into > account when applying a global regexp to a string. Because it will > actually start matching at `lastIndex`. So rather than the replace > function (which is ok, unless you're doing some serious searching or > need to stop after n matches) you could just loop it through. > > var match = null; > var matches = []; > var r = /(ab)b/g; > var s = 'aaabbabaaabbabababbaaabbab'; > while (match = r.exec(s)) { > matches.push(match); > } > > Oh and these match objects should have an `index` property that tell > you the start of the match. Of course this is a simple example where > it doesn't really make sense to actually save the matches like that, > but you probably want to apply it to a regex and string where the > results are not as predictable. > > - peter > > -- > To view archived discussions from the original JSMentors Mailman list: > http://www.mail-archive.com/[email protected]/ > > To search via a non-Google archive, visit here: > http://www.mail-archive.com/[email protected]/ > > To unsubscribe from this group, send email to > [email protected] -- To view archived discussions from the original JSMentors Mailman list: http://www.mail-archive.com/[email protected]/ To search via a non-Google archive, visit here: http://www.mail-archive.com/[email protected]/ To unsubscribe from this group, send email to [email protected]
