jemswira,
Is there anything faster than checking like this?

Yes. Or rather, maybe. It is hard to tell from your pseudo notation if you have a hash of arrays, a hash of hashes or just a hash with weird key/value pairs. Assuming you have a hash of hashes then yes. 

my @tocheck = qw/Apple Corn Pie Fish/;
my %checkfrom = (
    Meat => {
        Fish => 1,
        Apple => 1,
        Pork => 1,
        Bacon => 1,
    },
    Fruit => {
        Apple => 1,
        Pie => 1,
        Orange => 1,
        Beef => 1,
    },
);
for my $thing (@tocheck) {
    for my $category (keys %checkfrom) {
        delete $checkfrom{$category}{$thing};
    }
}

[download]
If your pseudo notation implied something else. Use real code and repost.

Cheers - L~R

In reply to Re: Removal of values in array from array list by Limbic~Region
in thread Removal of values in array from array list by jemswira

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.