6. Cascading Ifs (Chapter 6)

Cascading ifs are bad:

    if (condition) {
	$value = foo;
    } 
    elsif (condition) {
	$value = bar;
    }
    elsif (...) {
	$value = baz;
    }

You may be able to replace with a table lookup:

    my %hash = (
	...
    );
    if (defined $hash{value}) {
	$value = $hash{value};
    }

Or a tabular ternary:

    my $salute = $name eq $EMPTY_STR                       ? 'Dear Customer'
	       ? $name =~ m/ \A((?:Sir|Dame) \s+ \S+) /xms ? "Dear $1"
	       ? $name =~ m/ (.*), \s+ Ph[.]?D \z     /xms ? "Dear Dr $1"
	       :                                             "Dear $name"