use strict;
use Benchmark qw(cmpthese);

# A big, sorted list (475254 elements)
my @list = ('a'..'zzzz');
##Put the list into a string

my $string = join(/ /, @list);

$string .= "\n";

cmpthese(0, {
       # Looking for a random item in @list with grep
        index => sub {
                # A random element in the list
                my $pattern = 'fqsu  fqsv  fqsw  fqsx  fqsy';
                my $result = index($string, $pattern);

        },
        # Looking for a random item in @list linearly (with foreach)
        regex  => sub {
                my $pattern = 'fqsu  fqsv  fqsw  fqsx  fqsy';
                $string =~ /$pattern/;
        },
    }

);