I am not sure what you are trying to do. @{$file2_hash{$val}} is an array assigned to a hash key of $val. The array contains at least one string like "Chr12" and could potentially contain multiple ChrX strings. Whether there is just one or more than one Chr string depends upon the data.

The grep{} looks at all of the Chr strings and if one is found that matches $chr, then you get a "true" in the if statement.

It is easy to change the tests on the Chr strings. Looking for a range of hash keys (values) is a whole different story.

We are back to the same problem where your description of what you want is not clear.

In reply to Re^11: compare two files on the basis of Two IDs by Marshall
in thread compare two files on the basis of Two IDs by genome

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.