in reply to Re: Re: comparing two arrays
in thread comparing two arrays
If you need @file to contain at least all the elements of @report, then you need to find the simple difference of the two. The simple difference is the (paraphrasing from the Cookbook) "set of members of @report, but not of @file". If this set is empty, then @file contains at least all the elements of @report. So, working with Recipe 4.7:
(Array::Compare has a simple_compare() method, but it's definition of a simple compare is not the same as the Cookbook's.)use strict; my @report = qw(sqltable mike_test sarak_mike); my @file = (@report, qw(plus a little more)); # off by 0 print '@file was off by ' . simple_compare(\@report,\@file) . " elements\n"; # still 0, that elem wasn't in @report pop @file; print '@file was off by ' . simple_compare(\@report,\@file) . " elements\n"; # off by 1, that one was shift @file; print '@file was off by ' . simple_compare(\@report,\@file) . " elements\n"; # returns number of elements in A that aren't in B sub simple_compare { my ($A,$B) = @_; # build lookup table my %seen = map { $_ => 1 } @$B; # find those in A that aren't in B my @aonly; foreach my $item (@$A) { push @aonly,$item unless ($seen{$item}); } return scalar @aonly; }
Also note that this could only a be partial solution. What if you needed to compare these two arrays:
Now what? @file definitely contains at least one of each element from @report. But, @file doesn't contain 2 'one's like @report does. If you need something like this, but you don't care about order, then use rob_au's suggestion and sort the arrays first. If you do care about order, use that code verbatim. Hope this helps!my @report = qw(one one two); my @file = qw(one two two);
jeffa
L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
F--F--F--F--F--F--F--F--
(the triplet paradiddle)
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Re: (jeffa) 2Re: comparing two arrays
by jdelmedi (Initiate) on Nov 24, 2001 at 23:46 UTC | |
by jeffa (Bishop) on Nov 25, 2001 at 23:11 UTC |