$1 vs \1 in Perl regex substitutions
- by Mr Foo Bar
I'm debugging some code and wondered if there is any practical difference between $1 and \1 in Perl regex substitutions
For example:
my $package_name = "Some::Package::ButNotThis";
$package_name =~ s{^(\w+::\w+)}{$1};
print $package_name; # Some::Package
This following line seems functionally equivalent:
$package_name =~ s{^(\w+::w+)}{\1};
Are there subtle differences between these two statements? Do they behave differently in different versions of Perl?