5. More about || and &&

|| and && return the last argument that was evaluated. Thus, || is useful for assigning default values, like this: 

#!/usr/bin/perl

use strict;
use warnings;


# shift by default shifts from @ARGV in the main program
my $start = shift || 1;
my $end = shift || ($start+9);

for my $i ($start .. $end)
{
    print "$i\n";
}

Written by Shlomi Fish