#!/usr/bin/perl
use Modern::Perl;

my $str = 'thisthis';

my $n = $str =~ /this/g;
say $n;
$n = $str =~ /that/g;
say $n;
($n) = $str =~ /this/g;
say $n;
$n = () = $str =~ /this/g;
say $n;

#output
1

this
2