in reply to Re: Test if multiple variables are defined
in thread Test if multiple variables are defined

What about a simple grep like this?

s/^\s+|\s+$//g grep {defined $_} for ( $ipaddress, $prefix, $interface, $device, $locati;

That wouldn't work, s/// either works on the string binded to it with =~ (or !~) or on $_ otherwise, not on a list parameter. Look at AnomalousMonk's answer for the correct syntax.

  • Comment on Re^2: Test if multiple variables are defined

Replies are listed 'Best First'.
Re^3: Test if multiple variables are defined
by Laurent_R (Canon) on Jun 26, 2013 at 21:02 UTC

    Yes, you are right and I definitely know it. As noted in my update above, I really meant to write:

    s/^\s+|\s+$//g for grep {defined $_} ( $ipaddress, $prefix, $interface, $device, $location);

    But, as I also said in my update, that does not work as I expected, the "for" does not seem to deliver to the s/// statement the elements supplied by the grep. I got it working quite easily using a map instead of a for, but it no longer has the relative cleverness I was looking for.

[reply]
[d/l]

      use strict;
use warnings;
use Data::Dumper;

my ( $ipaddress, $prefix, $interface, $device, $location) = ('no_ws', 
+' some_ws ', undef, '  lotsa  ws  ', undef);
s/^\s+|\s+$//g for grep {defined $_} ( $ipaddress, $prefix, $interface
+, $device, $location);

print Dumper ( $ipaddress, $prefix, $interface, $device, $location);

      [download]
      (Thanks AnomalousMonk for the strings :D). So this yields: 
      $VAR1 = 'no_ws';
$VAR2 = 'some_ws';
$VAR3 = undef;
$VAR4 = 'lotsa  ws';
$VAR5 = undef;

      [download]
      It works fine.

[reply]
[d/l]
[select]

      Alright, I must have done something else wrong in my test. Thank you for your message.

[reply]

In Section Seekers of Perl Wisdom