Need help with regex

[minli98]

Hi,

I am very new to using regular expression, and I have a problem I can't figure out myself.

The problem is how do I write a reFindNoCase function that will pull up the value inside a <td> tag:

1:  <td>100</td>

2:  <td><span class="some_class"> -100 </span></td>

So, inside the <td></td> tag there is an optional <span> tag.  This tag is to be ignored, such that  (1) should give me 100 while (2) should give me -100.

I have played around with different regex strings, but I just can't figure it out.  Can someone help?

Thanks!

ML

[Owainnorth]

Probably not the neatest, but works:

<td>(<span(.*?)>)?(.*?)(</span>)?</td>

<td>               -- guaranteed string
  (<span(.*?)>)    -- a span tag with any characters inside, until a closing tag
               ?   -- the entire span tag is optional
  (.*?)            -- then the minimum number of characters until either:
  (</span>)?       -- an optional closing span tag
</td>              -- or the closing td

Group 3 should give you the value you need.

HTH.

[Adam Cameron. · Accepted solution]

Just a tip: if you want to group something for the purposes of applying a modifier to it, but you do not need to capture it for a back reference or a capture group, use the ?: modifier in the grouping, eg:

<td>(?:<span(?:.*?)>)?(.*?)(?:</span>)?</td>

That said, in this case one probably doesn't need the parentheses at all for the bit within the span, eg:

<td>(?:<span.*?>)?(.*?)(?:</span>)?</td>

--

Adam

[Owainnorth]

Wot he sed

[minli98]

Adam Cameron. wrote:

Just a tip: if you want to group something for the purposes of applying a modifier to it, but you do not need to capture it for a back reference or a capture group, use the ?: modifier in the grouping, eg:

Adam, I didn't know that tip and it turned out to be the difference.  Thank you so much!

MCL

[Adam Cameron.]

Cool. Good to see that random posts made whilst at the pub waiting for Eng v Italy to start (and mates to arrive to watch same) aren't such a bad idea.

--

Adam