NOT an array reference error in Perl

Question

I'm getting an error in Perl and I can't work out why.

Error: Not an ARRAY reference at Service.pm, line 20

my $array = [ { name => 'George', surname => 'Marley' } ];
my $helper = CustMessage->new();
$helper = CustMessage->getMessage($array);

then in my utility file I have:

sub getMessage {
    my ($self, $args) = @_;
    my $stringsArray = shift;

    my $strings = Service->new({
        serviceId => $self->_serviceId(),
    });

    return unless $strings;

    $strings->getStrings($stringsArray);
}

and then in the Service method is:

sub getStrings {
    my ($stringsArray, $self) = shift;
    my @keys = map({ $_->{'name'} } @{$stringsArray});
    my $key = join('', @keys); 
    $key = MIME::Base64::encode($key);

    my %results;
    $results{$key} = $self->_callStrings->($stringsArray);
    $results{$key}->initialize();

    $results{$key} = $self->{serviceCalls}->{getStrings};
    return $self->{serviceCalls}->{getStrings};
}

The error is on line 2 of the getStrings method in Service.pm:

my @keys = map({ $_->{'name'} } @{$stringsArray});

Nicely spotted but unfortunately that's not the issue. Think I accidentally removed that whilst copying and pasting (there's strange). — snakespan
– snakespan, Commented Dec 5, 2014 at 11:28
why is $helper an object first and then reassigned the value of the output of getMessage? I'm more used to seeing things like: my $helper = CustMessage->new(); my $msg = $helper->getMessage($array);. I guess if you don't use $helper again as an object then the reassignment works? Is this a typical pattern? — G. Cito
– G. Cito, Commented Dec 5, 2014 at 14:43

Borodin · Accepted Answer · 2014-12-05 11:46:21Z

2

The lines

my $helper = CustMessage->new();
$helper = CustMessage->getMessage($array);

are very odd. You are creating a new CustMessage object in $helper and immediately discarding it and overwriting it with the result of

CustMessage->getMessage($array);

which, apart from any inheritance that may be going on, is identical to

getMessage('CustMessage', $array);

and I am suspecting that you don't have a real class defined as you call it your "utility file"

Because getMessage receives its arguments like this

my ($self, $args) = @_;
my $stringsArray = shift;

you are left with

($self, $args) = ('CustMessage', $array)
$stringsArray  = 'CustMessage'

and you never use $args again so your array reference is lost.

I cannot be sure what it is you actually want, because, as I said, I suspect that you don't have a proper CustMessage.pm file. But you could try

my $helper = CustMessage->new;
my $message = $helper->getMessage($array);

and then

sub getMessage {
    my ($self, $stringsArray) = @_;

    ...
}

answered Dec 5, 2014 at 11:46

Borodin

127k9 gold badges72 silver badges146 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

G. Cito Over a year ago

Sort of off topic for the OP (whose issue has been resolved I guess) but see my comment above regarding: my $helper = CustMessage->new(); ... is it just superfluous code?

Borodin Over a year ago

@G.Cito: I'm not clear that the accepted answer catches all the errors in the question, but the OP seems happy. Take a look at my first paragraph -- you'll see that I agree with you about that line of code, although I'm not at all sure the OP has written a proper CustMessage.pm module as he calls it his “utility file”

G. Cito · Accepted Answer · 2014-12-05 14:47:29Z

1

RE: I'm getting an error in Perl and I can't work out why. Error: Not an ARRAY reference at Service.pm, line 20

Try

my ($self, $stringsArray) = @_;

instead of

my ($stringsArray, $self) = shift; 
# $self is always undef here due one element list assignment

since getStrings() is object method and object instance is always first element in @_ array.

edited Dec 5, 2014 at 14:47

G. Cito

6,4063 gold badges31 silver badges42 bronze badges

answered Dec 5, 2014 at 11:36

mpapec

50.7k8 gold badges71 silver badges133 bronze badges

1 Comment

mpapec Over a year ago

Please comment on which part is wrong in above answer when down voting.

Collectives™ on Stack Overflow

NOT an array reference error in Perl

2 Answers 2

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related