Why Doesn't this regex return a positive result?

I'm not familiar with regex and a temp programmer used this code.
        $pattern = '^[AD]([HF][12]|[Z][1])([0][1234569]|[1][0-9]|[2][123]|[3][34]|[4][0]|[5][1346])([0][12345679]|[1][0])([0][12345]|[1][03]|[2][03679]|[3][2389]|[4][01]|[5][1]|[9][5])([0][0123458]|[1][8]|[2][68]|[3][8]|[4][8]|[H][B])*^';
        
        //check if the product code matches a valid code pattern
        if(!preg_match($pattern, $pc)){
            $error = 'Please enter a valid product code';
        }

Open in new window

$pc is equal to "AF141020100"

I'm wondering if someone could explain how this code does not match the pattern specified.
dmleves49Asked:
Who is Participating?
 
Dan CraciunConnect With a Mentor IT ConsultantCommented:
Try this pattern to match:
$pattern='^[AD]([HF][12]|[Z][1])([0][1234569]|[1][0-9]|[2][123]|[3][34]|[4][01]|[5][1346])([0][12345679]|[1][0])([0][12345]|[1][03]|[2][03679]|[3][2389]|[4][01]|[5][1]|[9][5])([0][0123458]|[1][8]|[2][68]|[3][8]|[4][8]|[H][B])*$'

Open in new window

0
 
Dan CraciunIT ConsultantCommented:
Because it expects to be AF140, not AF141

HTH,
Dan
0
 
Ray PaseurCommented:
http://xkcd.com/1171/

Try writing down the rules for the product code.  I'll bet the regular expression could be a LOT simpler.
0
Increase Security & Decrease Risk with NSPM Tools

Analyst firm, Enterprise Management Associates (EMA) reveals significant benefits to enterprises when using Network Security Policy Management (NSPM) solutions, while organizations without, experienced issues including non standard security policies and failed cloud migrations

 
dmleves49Author Commented:
Thanks Dan. I was able to aquaint myself with regex enough to figure it out. The first two characters could only equal 33 or 34 if they started with a 3 or 40 if they started with a 4, etc.
0
 
Dan CraciunIT ConsultantCommented:
OK. So what was deficient in my answer?
See here for the grading guide: http://support.experts-exchange.com/customer/portal/articles/481419-what-grade-should-i-award-

In case of any other grade than A you are required to explain what was deficient about the solution.

Thank you.
0
 
dmleves49Author Commented:
I'm new here so I don't want to cause any problems as I appreciated everyone's help. I do however feel that getting the answer correct isn't actually what I requested.

I would have expected something like what I originally discovered. For Example:

The reason that your product code does not match the regex is because each set of parentheses is testing 2 digits. The first set of digits that do not match in your regex are "41" because [4][0] will only match "40". If you used [4][01] then it would match 40 or 41.

I'll upgrade your mark though. I just thought it required a bit of explanation since I said I wasn't familiar with regex.
0
 
dmleves49Author Commented:
Sorry Dan , I only saw your code comment, not your explanation. My bad.
0
 
Dan CraciunIT ConsultantCommented:
No worries, mate. Thanks for the points and welcome to EE.

Dan
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.