Although personally I'd still use a conditional, of course it's possible to do it all in one regex. One way is by making the comma optional by putting a ? on a group, in this case I'm using a non-capturing (?:...) group, and I had to make the first part of the regex non-greedy so that it doesn't swallow an existing comma:
use warnings;
use strict;
use Test::More;
my $regex = qr/ ^ (.*?) (?: , ([^,]*) )? $ /x;
ok "abc"=~$regex;
is $1, "abc";
is $2, undef;
ok "abc,5"=~$regex;
is $1, "abc";
is $2, 5;
ok "a,b,c,5"=~$regex;
is $1, "a,b,c";
is $2, 5;
done_testing;
Update: An alternative that says a little more explicitly: either match a string with no commas in it, or, if there are commas, I want to match the thing after the last one: /^ (?| ([^,]*) | (.*) , ([^,]*) ) $/x Update 2: And it turns out this regex is much faster than the above! (try using it in this benchmark)
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.