What is the correct way to break a line of Perl code into two?

$ cat temp.pl
use strict;
use warnings;

print "1\n";
print "hello, world\n";

print "2\n";
print "hello,
world\n";

print "3\n";
print "hello, \
world\n";

$ perl temp.pl
1
hello, world
2
hello,
world
3
hello, 
world
$

To make my code easily readable, I want to restrict the number of columns to 80 characters. How can I break a line of code into two without any side effects?

As shown above, a simple ↵ or \ does not work.

What is the correct way to do this?