freddo411 has asked for the wisdom of the Perl Monks concerning the following question:

Monks,

I'm using Class::DBI. I have the following syntax which won't work (in Perl 5.005) and I'm wondering how it can be done: 

use strict;
use warnings;

...snip...

   my $nn = "admin_contact_fk" ;
   my $foo = $record->$nn;

perl -c CDNR.pm
syntax error at CDNR.pm line 293, near "$nn;"
BEGIN not safe after errors--compilation aborted at CDNR.pm line 466.

[download]

Doesn't work... but...

   my $foo = $record->admin_contact_fk;

[download]

Does work.

Can someone explain how to use a variable with the "->" operator?

UPDATE: changed subject to include perl version

Please don't tell me to upgrade, as I don't control the production environment at my $firm.

-------------------------------------
Nothing is too wonderful to be true
-- Michael Faraday

Replies are listed 'Best First'.
Re: Syntax question (Perl 5.005)...
by chromatic (Archbishop) on Nov 07, 2003 at 22:10 UTC

    Does adding an empty argument list help distinguish this as a soft method call?

    my $foo = $record->$nn();
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Re: Syntax question...
by hardburn (Abbot) on Nov 07, 2003 at 21:34 UTC

    This code works for me:

    use strict; 

package foo; 
sub bar { print "Works\n" } 

package main; 
my $var = "bar"; 
foo->$var;

    [download]

    It's possible that your error is somewhere else. Perl's error messages are often, um, less then perfect at pointing to the real place the error is at.

    ----
    I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
    -- Schemer

    : () { :|:& };:

    Note: All code is untested, unless otherwise stated

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[select]
      Interesting. I copied your code and tried to run on my machine and got an error. Perhaps this is due to the fact I'm running on Perl 5.005. 

      gonzo:/export/home/fredk/docs/test: more foo.pl
#!/usr/local/bin/perl

use strict; 

package foo; 
sub bar { print "Works\n"; } 

package main; 
my $var = "bar"; 
foo->$var;

gonzo:/export/home/fredk/docs/test: ./foo.pl 
syntax error at ./foo.pl line 10, near "$var;"
Execution of ./foo.pl aborted due to compilation errors.

      [download]
      UPDATE

      This works if I change foo->$var to foo->$var();

      Can someone confirm this is a 5.005 thing?

      -------------------------------------
      Nothing is too wonderful to be true
      -- Michael Faraday

[reply]
[d/l]

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