Sort results by words occuring in array from grep(Perl)

Question

Any simple solution that Perl supports, which can sort results based on words occurring in array from grep?

For example you have a database which gets results from array grep and you want to show results first with the most repeated word which is matched.

Like a search engine which gives results by relevance.

Does that exists in Perl like in this expression:

@array_relevance = grep(/given_term/i, @old_array);

or

@array_relevance = grep{$_ =~ /given_term/i}@old_array;

where @array_relevance shows results first where "given_term" is occurring the most(like 5 times) and then shows results where "given_term" is occurring the least(4,3,2,1 times) descending

I mean "@old_array" is the data which contains multiple lines and it is a database which is in text file where there are titles, descriptions, time of submitted post etc.

Example of @old_array:

@old_array = "Title:Best marketing firm, Description:Check us out, we have many products which are innovative, Time of post:14:05:2015";

Then @array_relevance with grep selects its content which is requested showing results first which contain the most same terms descending.

Hope its understandable.

See [In Perl, how do I sort by frequency of a value?](http://stackoverflow.com/questions/4519979/in-perl-how-do-i-sort-by-frequency-of-a-value) — Håkon Hægland, Aug 18 '15 at 18:13
Seems like `@old_array` in your example only contains a single element. What is then the purpose of grepping? — Håkon Hægland, Aug 19 '15 at 12:50

stevieb · Answer 1 · 2015-08-18T19:52:15.733

0

It's difficult to figure out exactly what you need without any data, but try out the following:

use warnings;
use strict;

my @old = qw(nine one one one two three three);
my @given_terms = qw(one two three);

my %seen;
%seen = map {$_ => ++$seen{$_}} @old;

print "$_\n" for sort {$seen{$b} <=> $seen{$a}} @given_terms;

edited Aug 18 '15 at 19:52

answered Aug 18 '15 at 18:33

stevieb

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Wouldn't building `%seen` without a `for` loop make more sense, so you're not iterating `@old` multiple times grepping it? And then doing the sort from `@given_terms` rather than `keys`? – Sobrique Aug 18 '15 at 19:41
Yes, thanks Sobrique. I was looking at the problem backwards. – stevieb Aug 18 '15 at 19:52

Sort results by words occuring in array from grep(Perl)

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