I am trying to retrieve data from various nodes in an xml file. Unfortunately, there are times when the nodes have no values so i am trying to format the data to return a "0" or some character so that the output is consistent with files that do have values or text. thanks

#!/usr/bin/perl -w

  use strict;
  use warnings;

  my $filename = 'library1.xml';
  
  use XML::LibXML;

  my $parser = XML::LibXML->new();
  my $doc    = $parser->parse_file($filename);




    print $_->data . " | " foreach ($doc->findnodes('/library/cd/artis
+t/text()'));

  
    
    foreach ($doc->findnodes('/library/cd/artist')){
   my $artist = $_->to_literal;
   if $artist {
      print "$artist | ";
   
   else {
      print "0 | ";
   }
}
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XML file below - alternatives would be if artist "adele" were blank for example.

<library>
    <cd>
        <artist>adele</artist>
    </cd>
    <book>
      <title>Perl Best Practices</title>
      <author>Damian Conway</author>
      <isbn>0596001738</isbn>
      <pages>542</pages>
      <image src="http://www.oreilly.com/catalog/covers/perlbp.s.gif"
             width="145" height="190" />
    </book>
    <book>
      <title>Perl Cookbook, Second Edition</title>
      <author>Tom Christiansen</author>
      <author>Nathan Torkington</author>
      <isbn>0596003137</isbn>
      <pages>964</pages>
      <image src="http://www.oreilly.com/catalog/covers/perlckbk2.s.gi
+f"
             width="145" height="190" />
    </book>
    <book>
      <title>Guitar</title>
      <author>Mark Phillips</author>
      <author>John Chappell</author>
      <isbn>076455106X</isbn>
      <pages>392</pages>
      <image src="http://media.wiley.com/product_data/coverImage/6X/07
+645510/076455106X.jpg"
             width="100" height="125" />
    </book>
  </library>
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