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??

There are many issues with your code. First off though, always use strictures (use strict; use warnings; - see The strictures, according to Seuss). You use warnings, but strict is at least as important for catching errors. As another general coding tip: don't use the same name for multiple variables. In your sample code you use both $pro and @pro as well as @tetra and $tetra.

Although it is often a good idea to give a manifest constant a name so the intent of the constant is clear, using a variable for 1 called $one adds no information and is likely to cause confusion just because there seems no reason to use the variable.

Your "uninitialized value" variable warning is because you use @+ before the first regular expression match.

You aren't getting the number of iterations in the loop you expect because you update @pro within the loop. That is almost always a bad idea.

There are many ways to skin this cat. One trick is to use a look ahead match and take advantage of the fact that the regular expression engine doesn't allow successive matches at the same position. Consider:

#!/usr/bin/perl use warnings; use strict; my $pro = "ABCDEFGH"; my @tetras; push @tetras, [$1, $+[0] + 1] while $pro =~ /(?=(.{4}))/g; print "$_->[0] -> Starting at pos $_->[1]\n" for @tetras;

Prints:

ABCD -> Starting at pos 1 BCDE -> Starting at pos 2 CDEF -> Starting at pos 3 DEFG -> Starting at pos 4 EFGH -> Starting at pos 5
True laziness is hard work

In reply to Re: Is it possible to get all tetra words with correct starting position using a better code within a loop? by GrandFather
in thread Is it possible to get all tetra words with correct starting position using a better code within a loop? by supriyoch_2008

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
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            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 lurking in the Monastery: (8)
    As of 2015-07-04 21:41 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









      Results (60 votes), past polls