RE: [PHP] trying to match the front and end...

On 08 August 2003 17:39, Dan Joseph wrote: > Hi, > > > > In a nutshell, what I want to do is chop off the front and the > > > back. Example: > > > > > > I have: 1234567890 > > > I want: 456 > > > > > > I have a start num and an end num. start = 123, end = 7890. > > > > > > This is working fine as I have it above, however I'd like to > > > combine it into one regular express, instead of two. Can someone > > > give me an example of matching the beginning and end at the same > > > time? > > From Mike: > > > $middlenum = > > preg_replace("/^${this->start_num}(.*)${this->end_num}$/", '$1', > > $this->ach_acct_num); > > From John: > > > $new_number = > > > > preg_replace('/^'.$this->start_num.'([0-9]+)'.$this->end_num.'$/', > '\\1',$old > _number); > > The one that Mike gave didn't seem to do anything, Oops!! Forgot to escape the final $ in the pattern -- should have read: preg_replace("/^${this->start_num}(.*)${this->end_num}\$/", '$1', $this->ach_acct_num); > John's will work if it > can match the beginning and the end successfully. I should probably > explain myself further. > > Sometimes there won't be anything to replace at the front, and > sometimes nothing at the end. So it'd still need to do the front > and/or end wether or not they both exist. > > Is there a way to tweak these to do that? If $this->start_num or $this->end_num contains the empty string (or even NULL or FALSE), nothing will be interpolated into the string for those values, so the above (corrected) pattern will still work. If nothing-to-replace is signalled by something else, you may have a bit more work to do... Cheers! Mike --------------------------------------------------------------------- Mike Ford, Electronic Information Services Adviser, Learning Support Services, Learning & Information Services, JG125, James Graham Building, Leeds Metropolitan University, Beckett Park, LEEDS, LS6 3QS, United Kingdom Email: m.ford@lmu.ac.uk Tel: +44 113 283 2600 extn 4730 Fax: +44 113 283 3211