unitialized value in subroutine entry

[Anonymous Monk]

in a module, i have a routine. it has a "private function" (an anonymous routine).

if i print the anonymous routine as $<>; perl says it is a CODE ref; so that's good.

when the routine is invoked with &$<>; i get the following :

    Use of uninitialized value in subroutine entry at ...
and
    Can't use string ("") as a subroutine ref while "strict refs" in u
+se at ...

i could not find a good description of what these messages mean.

thanks

SIMPLE CASE :

sub A {
    if ( exists $OBJ->{$p} ) {
        my $q = $OBJ->{$p};
        $q = &$<package_name>::formatThis($q);
        print FH "$p=$q ";
    }

  my $formatThis = sub {
    my $x = @_;
      my $y = sprintf ( "%.2f", $x);
      return $y;
  };
}

Formatting fixed by GrandFather

[madtoperl]

Hi Ananymous Monk,

These like issues i faced previously when you give use strict and some initialization issues,So you remove the use Strict; statement in the code and run it.Othersiwe do the proper initialization there.Hope this will solve your issue.

Thanks and Regards,
madtoperl.

[Anonymous Monk]

yes, i am trying to identify exactly what are the initialization issues. the anonymous routine is code; and the first invocation has a valid parameter. in addition; "no strict" did not hide these messages. thanks

[dsheroh]

So you remove the use Strict; statement in the code and run it.

Ack! Tppppbbbbttt! If code won't run under strict, then turning strict off is not the way to fix it. If you do that, the real, underlying problem will still be there, you just won't get told about it - until the code blows up in your face.

[reneeb]

The variable $formatThis is not known as a "package-variable", because it just a variable for the subroutine. You can do it this way:

#!/usr/bin/perl

use strict;
use warnings;

my $OBJ = {test => 3};
my $p = 'test';




A();

sub A {
      
    my $formatThis = sub {
      my ($x) = @_;
      my $y = sprintf ( "%.2f", $x);
      return $y;
    };
  
    if ( exists $OBJ->{$p} ) {
        my $q = $OBJ->{$p};
        $q = $formatThis->($q);
        print "$p=$q ";
    }
  
  $formatThis;
}

[Anonymous Monk]

i'm sorry, but i don't follow much of your comments.

• variable
  my simple code example with the <package_name> string was to show that the subroutine variable still needs the package namespce. i find this odd; the subroutine was declared "my" all scalar/array/hash variables don't need a package name prepended to them when used in a function. to my simple mind, the code variable shouldn't need one.
• code snippet
  assuming that the second invocation of formatThis is a typo, i still get both error messages.
• error messages
  if someone could point me to a URL that defines these two messages; that would be a huge help. as i said earilier; i have both the input parameters and the code variable "provably" defined; so i'm curious what perl thinks is unitialized.

Formatting fixed by GrandFather

[shmem]

Back to your original example, with comments:

# $formatThis is not known here

sub A {                     # begin of subroutine
    # what is $OBJ ? is it a global variable? or is it passed into thi
+s sub?                         
    # what is $p ?   is it a global variable? or is it passed into thi
+s sub?
    if ( exists $OBJ->{$p} ) {
        my $q = $OBJ->{$p};
        $q = &$<package_name>::formatThis($q); # wrong! <package_name>
+ means:
                               # read one record from filehandle 'pack
+age_name'
        print FH "$p=$q ";
    }

  my $formatThis = sub {    # $formatThis declared as my(), lexically 
+scoped
    my $x = @_;             # wrong! evaluates @_ in scalar context!
      my $y = sprintf ( "%.2f", $x);
      return $y;
  };
}                           # end of subroutine

# from here on $formatThis is not known

I guess you want to say something like this, but I can't know, because you don't tell us about the context of your code:

sub A {
    my ($OBJ,$p) = @_;
    if ( exists $OBJ->{$p} && exists $OBJ->{'sub'}) {
        my $q = $OBJ->{$p};
        $q = $OBJ->{'sub'}->($q); # execute the sub stored in $OBJ
        print STDOUT "$p=$q\n";
    }

    my $formatThis = sub {
      my ($x) = @_;
        my $y = sprintf ( "%.2f", $x);
        return $y;
    };
    $OBJ->{'sub'} = $formatThis;
}
# test it
my $ref = {};
$ref->{'float'} = 3.1415926;
A($ref);         # get a sub
A($ref,'float'); # now doit

--shmem

[Anonymous Monk]

Hi,
hmm....I removed that one and that issue solved.some other issue i will check that.