You have to make a distinction between empty file (size of 0 bytes) and a file full of blanks (tabs and newlines). The latter will have non-zero size.

In your first code the only way to get a zero-size file would be if %chrsize is empty and foreach $chr (keys %chrsize){ does not loop at all. If $chrsize{$chr} is not defined (i.e. $size=undef) or if it is zero (i.e. $size=0), the foreach $index (0..$size) { will still loop once with $index = 0

You second code is much more likely to produce a zero-size file.

BTW, foreach $index (0..3) loops for 0, 1, 2 AND 3

You really need to use strict; use warnings;

In reply to Re: If Condition causes totally blank Output File/Issue in Writing to Output by bliako
in thread If Condition causes totally blank Output File/Issue in Writing to Output by hghosh

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.