#! /usr/bin/perl
use strict;
use warnings;

my @array = qw (one two three four five);
my %hash = (one => 'Extra information for one',
two => 'Extra information for two');

foreach my $id (@array) {
	if (exists $hash{$id}) {
		print "ID: $id has extra info: $hash{$id}\n";
	}
	else {
		print "ID: $id has no extra info\n";
	}
}