Perl Checking if a scalar contains one of the elements in an array

Question

I have an array

my @array = qw/FOO BAR BAZ/;

and a scalar read from a file containing data like

Answer 1

That is exactly what grep is for. Here's a small snippet:

use strict;
use warnings;

my $str = "+++123++585+++FOO";
my $blank = "+++123++585+++XYZ";
my @array = qw/FOO BAR BAZ/;
print grep {$str =~ $_} @array, "\n";
print grep {$blank =~ $_} @array, "\n";

This would just return:

FOO

grep, reduce and map are what we call higher order functions in FP world, though reduce might be called fold there. Have a look at MJD's Higher Order Perl for more of these.

• grep
• map
• reduce
• Higher Order Perl

Answer 2

Yes, there is far better way. You can construct regular expression. It will be alternatives of fixed strings which is fortunately translated into trie (Aho-Corasick) which leads into linear search time. It is the most efficient way at all.

my @array = qw/FOO BAR BAZ/;
my $re = join '|', map quotemeta, @array;
$re = qr/$re/;

for my $string (@strings) {
  if ($string =~ $re) {
    ...
  }
}

Answer 3

You can create a regex that matches all of the @array:

my $regex = join '|', map quotemeta, @array;
$string =~ $regex;