Why does my method print "isObjectName=SCALAR(0x1289df0)"?

Question

New to OOP with Perl, and just had a quick question. I have this function in a class:

sub Print{
    my $text = shift;
    print "my text is", $text;
}

I try to print the text out, by doing this:

my $object = ObjectName->new();
$object->Print("Print this text")

It prints this:

my text isObjectName=SCALAR(0x1289df0)

My question is, why does it do this and how can I get it to simply print the text I pass as an argument?

Answer 1

This:

$object->Print("Print this text");

Is (mostly) equivalent to this:

ObjectName::Print($object, "Print this text");

The first argument to any method is $self, which is a blessed reference and looks all ugly when you print it like that. You want to print the second argument. See perlboot and perltoot for more info.

Answer 2

Change your method to:

sub Print{
    my ($self, $text) = @_;
    print "my text is", $text;
}

When you call a method on an object in Perl (i.e. when you go $object->Print(...), in this case), the first argument passed to the method is the object itself.

Answer 3

When you have these sorts of problems, check your argument list to see what's going on:

use Data::Dumper;

sub Print {
     print Dumper( \@_ ), "\n";
     ...;
}

You should almost never suspect Perl as the source of a bug, at least until you've eliminated almost everything else.