@nums{ @numbers } = (1) x @numbers;

##</code><code>##

#!/usr/bin/perl -w       
use strict;
use Data::Dumper;

my @array = (1, 3, 5, 7, 9);
my @numbers = (1, 4, 6 , 8);

my(%nums, %rums);

@nums{ @numbers } = 1;
@rums{ @numbers } = (1) x @numbers;
         
print Dumper \%nums;
print Dumper \%rums;

##</code><code>##

$VAR1 = {
          '8' => undef,
          '1' => 1,
          '4' => undef,
          '6' => undef
        };
$VAR1 = {
          '8' => 1,
          '1' => 1,
          '4' => 1,
          '6' => 1
        };

##</code><code>##

@nums{ @numbers } = ();
print "FOUND\n" if exists $nums{ $array[0] };