Need some help with an regex

Posted on 2005-05-01
Medium Priority
Last Modified: 2006-11-18
ok for my program i have an discoutn field.  The discount can be an amount or a percent.

I wrote these regex

// Figures out if it's it's an valid amount
// Figures out if it's it's an valid percent

// which i turned into this statement....

here is the output of my test script...

here is my script

ok my problem is that after i did that i realzed that i needed a preg_match statement and that for some reason my regular expression doesn't work and i have no information on how a preg_match statement is different from a regex one

As always any ideas, links or help is greatly appreciated..
Question by:mightofnight
LVL 27

Assisted Solution

Diablo84 earned 1000 total points
ID: 13904735
You need to add a forward slash ("/") to the beginning and end of your patterns and then call:
if (preg_match($test_ereg, $data)) {

Quote from:


"The syntax for patterns used in these functions closely resembles Perl. The expression should be enclosed in the delimiters, a forward slash (/), for example. Any character can be used for delimiter as long as it's not alphanumeric or backslash (\). If the delimiter character has to be used in the expression itself, it needs to be escaped by backslash. Since PHP 4.0.4, you can also use Perl-style (), {}, [], and <> matching delimiters."

Related reference:

preg_match maunal entry: http://us4.php.net/manual/en/function.preg-match.php
pattern syntax: http://us4.php.net/manual/en/reference.pcre.pattern.syntax.php

... note that with perl compatible regex you can optionally use \d instead of [0-9] which represents any decimal digit


Accepted Solution

jdpipe earned 1000 total points
ID: 13908245

I just tested this with your $string array and it seemed to work:

foreach($string as $s){
            print("amount: ".round($matches[1],2));
            print("percent: ".round($matches[1],4));

Author Comment

ID: 13913784
I got it to work :D


ok thanks for both of your comments..

jdpipe i am unable to directly use the statement you setup brecause this regex is going to be used in three different places... javascript form validation, regular form validation and and to determin the data type as needed.  Thouhg the example you provided did help me understand some of the syntex that i needed to change.  

Diable84 Thanks for the comment.  I wasn't really looking for a php.net link seeing as thats always the first place i look.  gotta love the quick searching php.net/*name of function or command here that you are looking for*.  But you did point me to a spot that i had overlooked.

THanks again guys


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