hey all--
I'm working on a method in my first OO project which seems like it should be simple but ended up pretty complex (and still doesn't DWIW). The idea is that I only want to allow certain values to be passed as parameters, and I want to assign a default if the value passed is not one of the legal ones. Here my attempted WTDI:
#! perl -w
use strict;
package Test;
sub new {
my $class = $_[0];
my $self = {'associations' => undef,
'balance_by' => undef,
'comment' => undef};
bless $self, $class;
return $self;
}
sub balance_by {
my $self = shift;
my $entry = shift;
my %valid_params = map {$_ => 1} ('foo',
'bar');
unless (defined $self->{'balance_by'}) {
$self->{'balance_by'} =
(defined $entry && $valid_params{$entry})
? $entry
: 'foo';
}
return $self->{'balance_by'};
}
my $lex = Test->new();
$lex->balance_by('bar');
print $lex->balance_by();
initially this seemed to work fine, but when I went back and added the line
print $lex->balance_by('baz')
it still prints "bar". I realize now that the way I used the
unless loop makes it impossible to update the value once it has been defined once, but I am at a loss. How should I go about doing this?
thanks in advance,
--au
this was going to be a question about lists, arrays, $_, @_, and shift, but an excellent CB discussion unmuddied my head a bit (or at least showed me that the subject is inherently muddy ;-)
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.