#!/usr/bin/env perl # use strict; my @someList = ('abc', 'def', 'ghij', 'klm'); my @someOtherList = ('abc', 'def', 'ghij'); # # to compare the elements of one list with another # # 1. method: make a dictionary and check for entries # my %someOtherHsh = map { $_ => 1 } @someOtherList; foreach my $elm (sort @someList) { if( ! defined( $someOtherHsh{$elm})) { print "$elm is not @someOtherList\n"; } } # # 2. method: use grep # foreach my $elm (sort @someList) { if( ! grep /$elm/, keys %someOtherHsh) { print "$elm is not @someOtherList\n"; } }