I have to do an operation of each key of a hash that isn't listed in a "@do_not_want" array.

How can I get this to work? 
#!/usr/bin/perl -w

use strict;


my %hash;

#  don't want these keys in the subroutine
$hash{'ytd'} = 1.5;
$hash{'mtd'} = 2.0;
$hash{'wtd'} = 2.5;


#  store what I don't want here
my @do_not_want = qw{ ytd mtd wtd };


#  want these keys and any others in subroutine
$hash{'Jumbo_Tron'} = "United Center";
$hash{'Meat_Pie'} = "Gross";
$hash{'Word'} = "Association";


#  my try, grepping each item in @do_not_want into a larger grep
foreach my $anything_but ( grep { grep { }, @do_not_want }, keys %hash
+ ) {

    #  print every key except for "ytd", "mtd", and "wtd"
    print $anything_but . "\n";

}

[download]

In reply to Selecting a Specific Keys in Relation to a List by awohld

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.