#!/usr/bin/perl -w

use strict;

my @a = (10, 20, 30);
my @b = (11, 20, 30);


sub item_exists {
    @_{@_}    =   1;
    $_{$_[0]} ? 0:1;
}


print "10 ", item_exists(10, @a) ? "is   ": "isn't", " in qw(@a).\n";
print "11 ", item_exists(11, @a) ? "is   ": "isn't", " in qw(@a).\n";
print "10 ", item_exists(10, @b) ? "is   ": "isn't", " in qw(@b).\n";
print "11 ", item_exists(11, @b) ? "is   ": "isn't", " in qw(@b).\n";
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