$foo = $bar || 'baz';
# is identical to
$foo = ( $bar or 'baz');

##</code><code>##

open( $fh, '>', $filename ) or die "Unable to open file: $!";

my $foo = $bar || 'baz';

##</code><code>##

# Original code
$self->{'Post'} = ($args{'Post'} or sub {1;});

# High precedence or
$self->{'Post'} = $args{'Post'} || sub {1};

# Ternary operator
$self->{'Post'} = $args{'Post'} ? $args{'Post') : sub {1};

# Using '||' for a numeric value.
$self->{'Number'} = $args{'Number'} || 10;

##</code><code>##

foo();
foo(23);
foo(0);

sub foo {
    my $number = shift || 10;
    print "My number is $number\n";
}

__END__ #OUTPUT:
My number is 10
My number is 23
My number is 10

##</code><code>##

foo();
foo(23);
foo(0);

sub foo {
    my $number = shift // 10;
    print "My number is $number\n";
}

__END__ #OUTPUT:
My number is 10
My number is 23
My number is 0