Beefy Boxes and Bandwidth Generously Provided by pair Networks
Don't ask to ask, just ask
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

A comment on the regexen:

# regex to add a comma after each char # i believe you can think of it starting # at the second character since # ?<= means look to the left of the current # position # the . means to look at one character # the () are required to capture each character $show_choices =~ s/(?<=.)/,/g; $show_choices =~ s/,$//g; # remove the last comma

Actually, there is no capturing being done in the first regex; the parentheses are there only for grouping, i.e. to show where the positive look-behind assertion ends. (Try adding a $1 to the replacement part, and you will get a series of error messages beginning Use of uninitialized value $1.)

The first regex could also be written as:

$show_choices =~ s/(.)/$1,/g;

which does capture each character.

The two regexen can be combined into one using a negative look-ahead assertion:

$show_choices =~ s/(.)(?!$)/$1,/g;

See “Look-Around Assertions” under Extended Patterns in perlre.

Hope that helps,

Athanasius <°(((><contra mundum Iustus alius egestas vitae, eros Piratica,


In reply to Re: Perl replacement for choice.com by Athanasius
in thread Perl replacement for choice.com by onelander

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others about the Monastery: (5)
    As of 2014-09-18 05:46 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      How do you remember the number of days in each month?











      Results (108 votes), past polls