Re^2: How to call a sub reff from a hash

[NateTut]

I think you've goten me on the right track, but this:

#!/usr/bin/perl
use strict;
use warnings;

sub Procedure_Name_1
   {
   my($Parm) = shift;
   print($Parm);
   }

my %Procedures;
$Procedures{'ProcName1'} = \&Procedure_Name_1;

my $Procedure = 'ProcName1';
my $Parameter = 'Some Value';
&$Procedures->{$Procedure}($Parameter);

still fails...

[Fletch]

Because you have no scalar $Procedures declared (you have a hash %Procedures, but that's something completely different).

[NateTut]

Yes, but I'm trying to access an element of that hash.

[ikegami]

Your wrong code:

$Procedures->{$Procedure}($Parameter);
^^^^^^^^^^^
  Not a hash. Undeclared and uninitialized scalar.

The correct code:

$Procedures{$Procedure}->($Parameter);
^^^^^^^^^^^^^^^^^^^^^^^
  Element of a hash

[Fletch]

Then you want to re-read perldata and perlreftut because $foo->{'bar'} has nothing to do with trying to get at $foo{'bar'}.

[Joost]

For that you want

&{$Procedures{$Procedure}}($Parameter);
# or
$Procedures{$Procedure}->($Parameter);

And yeah, the syntax may be confusing, but that's just how references work.

[eric256]

Taking your code and then switching the last line like he said makes it work perfectly.

#!/usr/bin/perl
use strict;
use warnings;

sub Procedure_Name_1
   {
   my($Parm) = shift;
   print($Parm);
   }

my %Procedures;
$Procedures{'ProcName1'} = \&Procedure_Name_1;

my $Procedure = 'ProcName1';
my $Parameter = 'Some Value';
$Procedures{$Procedure}->($Parameter);

I don't understand why you ignored his advice but i would recommend trying it as written in the future.

BTW you could read the last line as "get the value of $Procedures{$Procedure} and then run it as a coderef ->( passing it $Parameter)"