#!/usr/bin/perl

use strict;
use warnings FATAL => 'all';
use feature 'say';

say '1';

if (1) {{
    say '2';
    last;
    say '3';
}}

say '4';

__END__
output:

    $ perl script
    1
    2
    4

without double {{ :

    $ perl script
    1
    2
    Can't "last" outside a loop block at c.pl line 11.