If your program executes, that's a hint that this is just a warning, and not an error. Perl programs abort on errors (unless otherwise provided for).

Read the message - it is complaining about concatenation. More likely the error is in the print statement following. If $start_of_barrel_region is undefined, $s will be too, and so then $hash_plp_lbl_barrel_region_only{$s} will be undefined because the key is undefined. Once the loop body has executed once, the $s++ will make $s now be 1, and you won't see the warning again.

Use the debugger to inspect the values to make sure they are what you expect.

Dum Spiro Spero

In reply to Re: Is this a severe error? by GotToBTru
in thread Is this a severe error? by Anonymous Monk

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!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • 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, details, 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, summary, 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.