i copied the code as is, and got no error.
are you sure line #29 is where you are calling $_incr_count->()?
are you sure the code you are executing is what you posted?
On Wednesday, March 27, 2002, at 06:47 PM, Paul Tremblay wrote:
> I am coppying the code below directly from *Object Oriented
> Perl* by Conway. (Error message is below.)
>
>
> package CD::Music;
> #use strict; # turn this off for testing purposes
>
> {
>
> my $_count = 0;
> sub get_count {$_count}
> my $_incr_count = sub {++$_count};#create an anonymous subroutine
> $_incr_count->();# it works if I call it here
>
> sub new{
> $_incr_count->();#call the anonymous subroutine
> #this line above causes the error below
>
>
> #Isn't this where the anonymous subroutine should go?
> #my $_incr_count = sub {++$_count};
>
>
> my ($class) = @_;
> bless {
> _name => $_[1], #second value passed to subroutine
> _artist => $_[2], #third value passed to subroutine
> _publisher => $_[3], #and so on
> _ISBN => $_[4],
> _tracks => $_[5],
> _room => $_[6],
> _shelf => $_[7],
> _rating => $_[8],
> }, $class;
> }
> }
>
> I am getting this error message:
>
> /home/paul/bin/test16.pl
> Use of uninitialized value in subroutine entry at /home/paul/bin/test16.pl
> line 29.
> Undefined subroutine &main:: called at /home/paul/bin/test16.pl line 29.
>
> I am nearly positive that this error message results because the
> reference to the anonymous subroutine expires once I start the
> subroutine new.
>
> Could a more experienced user confirm this?
>
> I believe that the annonymous subroutine (and the other code
> that initializes the counter) should go in the new subroutine
> block. The idea is make sure you can't access the subroutine
> directly. This happens as long as I make an anonymous
> subroutine--no matter where I put it.
>
> Thanks!
>
> PS: Typos in computer books can really cause you to lose your
> mind. You keep thinking that you typed something wrong!
>
> --
>
> ************************
> *Paul Tremblay *
> *[EMAIL PROTECTED]*
> ************************
>
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