hash ref as member of class

bob_dobalina has asked for the wisdom of the Perl Monks concerning the following question:

How would i properly access "hash reference member"? See "PrintHash" for what I'm trying to do. Thanks.

X.pm:

package X;

sub new
{
    my ($class)  = @_;
    
    my %ht = ();
    %ht= ("x" => "y");
    my $self = 
    {    
        HREF => \%ht,

    };

    bless $self, $class;
    return $self;
}
sub PrintHash
{
    my($self) = @_;
    # this doesn't work ("scalar found where operator expected"):
    # while( my ($k, $v) = each (%$self->{HREF}) ) 
    # . . .
}

1;
[download]

main.pl:

use X;
my $x = new X();
$x->PrintHash();
[download]

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Replies are listed 'Best First'.
Re: hash ref as member of class by JavaFan (Canon) on Aug 11, 2009 at 16:22 UTC
Almost there. `each %{$self->{HREF}}` should do. In general, if you have an expression (`$self->{HREF}` is an expression) that yields a hashref, putting `%{ }` around that expression gives you the hash.	[reply] [d/l] [select]
Re^2: hash ref as member of class by Fletch (Bishop) on Aug 11, 2009 at 16:52 UTC
Just as an aside for the OP why your initial try was wrong: your `%$self->{HREF}` parses as `(%{$self})->{'HREF'}` because `%$self` is a complete term to which the `->` deref operator is (unsuccessfully) applied. Using the curlies works kind of like specialized parens letting perl know that what you want to dereference is the hashref the expression `$self->{HREF}` contains. The cake is a lie. The cake is a lie. The cake is a lie.	[reply] [d/l] [select]
Re^3: hash ref as member of class by bob_dobalina (Sexton) on Aug 11, 2009 at 20:19 UTC
thanks that makes sense. I initially tried %($self->{HREF}) w/ parens instead of curly braces. perl is confusing like that - you initalize a hash with parens, access and derefence with curly braces, etc.	[reply]
Re^4: hash ref as member of class by JavaFan (Canon) on Aug 11, 2009 at 21:34 UTC
Re^2: hash ref as member of class by bob_dobalina (Sexton) on Aug 11, 2009 at 20:15 UTC
gracias! that did it	[reply]