#!usr/bin/perl use strict; use warnings; use feature 'say'; use Data::Dumper::Simple; use List::Compare; my @dead_list = (100, 101, 103, 200, 201, 202, 203, 210, 211, 212, 220, 221, 222, 230, 231, 232, 233, 240, 241, 242, 243, 1000, 1001, 1002, 1010, 1011, 1012, 1020, 1021, 1022, 1120, 1121, 1122, 1210, 1211, 1212); my @get_list = ( '100', '200', '210', '220', '230', '240', '1000', '1001', '1002', '1120', '1210',); my $lc = List::Compare->new(\@dead_list, \@get_list); my @result = $lc->get_unique; say Dumper(@result); __END__ @result = ( '101', '1010', '1011', '1012', '1020', '1021', '1022', '103', '1121', '1122', '1211', '1212', '201', '202', '203', '211', '212', '221', '222', '231', '232', '233', '241', '242', '243' );