What is an unblessed reference error?

[Wiinie]

How can I fix the error "Can't call method "id" on unblessed reference" for the following code?

sub language{
	my $self = shift;
	if (!$self->{LANGUAGE})
	{
		my @language = ();
		my $statement = $db->prepare("select  languageId, languageName
										from language");
		$statement->execute();
		
		while(my @array = $statement->fetchrow_array()){
			my ($id , $name) = @array;
			my $object = Language->new();
			$object->id($id);
			$object->name($name);
			push (@language, $object);	
		}			
		$self->{LANGUAGE} = \@language;
	}
	return $self->{LANGUAGE};
}

my @languagetest = language();

			foreach my $current(@languagetest){
			my $id = $current->id();
			my $name = $current->name();
			print "RETURN ID: [$id]  Name: [$name] \n";
			}

[miller]

You do not show the code where the problem occurs. You create an object there:

my $object = Language->new();

Therefore in the new method of the Language class, you should be returning a blessed data structure as is required in perl OOP (Object Oriented Prgramming). Where's your new method? are you blessing a hash or such?

perldoc: perltoot - Tom's object-oriented tutorial for perl

- Miller

[Wiinie]

I try using foreach to print out the result

# my @languagetest = language();
#  
#             foreach my $current(@languagetest){
#             my $id = $current->id();
#             my $name = $current->name();
#             print "RETURN ID: [$id]  Name: [$name] \n";
#             }

and it gives me an error of unblessed reference when i call the method id() again.. please help me to solve this problem. or does it have another to print out the result.

[miller]

Yes, because $current is not an object. You should know what type of data structure $current is, but if you don't use Data::Dumper

use Data::Dumper;

my @languagetest = language();

foreach my $current (@languagetest) {
	print Dumper($current);
	my $id = $current->id();
	my $name = $current->name();
	print "RETURN ID: [$id] Name: [$name] \n";
}

[Wiinie]

Thank so very much for the above answer.
And I have another question as well. I did use the selectall_array _ref to execute this query. and when I try to print in the sub nextWords. it does work and prints out all the result that i have expected.

sub nextWords {
	my ($id, $offset) = @_;
	my @array = ();
	my $statement = $db->selectall_arrayref("select word from words 
			left outer join language
			on words.languageId = language.languageId
			where words.languageId = $id
			order by word asc
			limit 10 offset $offset;");
			
	my @main= ();
	foreach my $i (@$statement)
	{
		push(@main, @{$i}[0]);
	}
	@array[$id] = [@main];
	
	return  @array; 
}	

my $lang_size = languages();
for my $id(1 .. $lang_size ){
	
	print "=======ID = " . $id . "=======\n";
	my $self->{CURRENTOFFSET}  = 0;
	NAME: while (1 > 0){
		my @newwordsList = nextWords($id,$self->{CURRENTOFFSET});
		
		$self->{CURRENTOFFSET}+= 10;
		
		foreach my $k (@{@newwordsList[$id]}) {
			print $k . "\n";
		}
		print "\n";
		if (!@{@newwordsList[$id]}[0]) {
			last NAME;
		}
	}
}

However, when i try to print out by create and other file.pl to compile it. it doesnt work, it give an error "DBD::SQLite::d b selectall_array ref failed: unrecognized token: "0x1db16c".

$object = DataLayer->new();
print $object->nextWords();

for my $id( 1 .. 3)
	{
		my $offset= 0;
		NAME: while (1>0)
		{
			my @wordList = $object->nextWords($id, $offset);
			$offset+=10;
			foreach my $k (@{@wordList[$id]}) {
			print $k . "\n";
			}
			if (!@{@wordList[$id]}[0]) {
			last NAME;
			}
		}	
	}

thanks in advance..