How do I interact with a Perl object that has a hash attribute?
- by brydgesk
I have a class with several variables, one of which is a hash (_runs):
sub new
{
my ($class, $name) = @_;
my $self = {
_name => $name,
...
_runs => (),
_times => [],
...
};
bless ($self, $class);
return $self;
}
Now, all I'm trying to do is create an accessor/mutator, as well as another subroutine that pushes new data into the hash. But I'm having a hell of a time getting all the referencing/dereferencing/$self calls working together. I've about burned my eyes out with "Can't use string ("blah") as a HASH ref etc etc" errors.
For the accessor, what is 'best practice' for returning hashes? Which one of these options should I be using (if any)?:
return $self->{_runs};
return %{ $self->{_runs} };
return \$self->{_runs};
Further, when I'm using the hash within other subroutines in the class, what syntax do I use to copy it?
my @runs = $self->{_runs};
my @runs = %{ $self->{_runs} };
my @runs = $%{ $self->{_runs} };
my @runs = $$self->{_runs};
Same goes for iterating over the keys:
foreach my $dt (keys $self->{_runs})
foreach my $dt (keys %{ $self->{_runs} })
And how about actually adding the data?
$self->{_runs}{$dt} = $duration;
%{ $self->{_runs} }{$dt} = $duration;
$$self->{_runs}{$dt} = $duration;
You get the point. I've been reading articles about using classes, and articles about referencing and dereferencing, but I can't seem to get my brain to combine the knowledge and use both at the same time. I got my _times array working finally, but mimicking my array syntax over to hashes didn't work.
