$appid{$id} = $name->string_value; So what do you think putting braces around then contents did?
What do braces mean?
What happens when there isnt an even number of values inside braces?

You need to understand the answers to those questions or you will just keep getting into trouble.

Your question really make sense ,but i wont able to complete understand it..Sorry for that.. if i use $appid{$id} = $name->string_value getting this error Odd number of elements in anonymous hash at comparexml.pl line 21. I dont know much in perl ,just got some work todo... How i can resolve it please help ?

I dont know much in perl ,just got some work todo

I dont know much in perl ,just got some work i'm trying to get someone to do for me.

Fixed it for you

Get string values before regex

#!/usr/bin/env perl       
use strict;
use warnings;
use XML::XPath;
use Data::Dumper;

my $xml = 'ApplicationList.xml';
my $xp = XML::XPath->new(filename => $xml);
my $appxpath =  $xp->findnodes("//application_list/application"); # no
+ end /
my %appid = ();

foreach my $appnodeset ($appxpath->get_nodelist) {
  my $id   = $xp->find('./@id',$appnodeset)->string_value;
  my $name = $xp->find('./@name',$appnodeset)->string_value;
  s/^\s+|\s+$//g for $id,$name;
  $appid{$id} = $name;
}
print Dumper \%appid;
[download]

You are really a monk saver for me ...!!! Please do help me with 1more small query ... as per the code u shared yesterday i am getting eventid and name in diff arrays.. But Now i want out put as :

required output

$VAR1 = [
          {
            'eventid' => '957',
            'name' => 'aaaa'  
          },
          {
            'eventid' => '2667',
            'name' => 'bbbb'
          },
          {
            'eventid' => '2667'
            'name' => 'bbbb'
          },
          {
            'eventid' => '1503'
            'name' => 'cccc'
          },
          {
            'eventid' => '1103'
            'name' => 'dddd'
          },
          {
            'eventid' => '1503'
            'name' => 'cccc'
          }
        ];
[download]

How can i do with multiple loop :

#!/usr/bin/env perl       
use strict;
use warnings;
use XML::XPath;
use Data::Dumper;

my $xml = 'ApplicationList.xml';
my $xp = XML::XPath->new(filename => $xml);
my $appxpath =  $xp->findnodes("//application_list/application/");

my %appid = ();
foreach my $appnodeset ($appxpath->get_nodelist) {
  my $id   = $xp->find('./@id',$appnodeset)->string_value;
  my $name = $xp->find('./@name',$appnodeset)->string_value;
  s/^\s+|\s+$//g for $id,$name;
  $appid{$id} = $name;
}
print Dumper \%appid;

my $eventxml = 'events.xml';
my $evenxp = XML::XPath->new(filename => $eventxml);
my $xpath = "//event/custom_attribute_list/custom_attribute[normalize-
+space(name)='SLB_SSRID']/value";

my @eventrecords = ();
foreach my $node ($evenxp->findnodes($xpath)) { 
  my $ssrid = $node->string_value;
  $ssrid =~ s/^\s+|\s+$//g ;
  if ( exists $appid{$ssrid} ){
    push @eventrecords, 
      { eventid => $ssrid };
  } 
}
print Dumper \@eventrecords;
[download]

Thanks for helping .

 if ( exists $appid{$ssrid} ){
    push @eventrecords, 
      { eventid => $ssrid,
        name    => $appid{$ssrid},
      };
  }
[download]

I'm working on below code and want to sort the records with event id and then add index number to each array .. But know i am first getting whole list of event ids and then line ..

#!/usr/bin/env perl       
use strict;
use warnings;
use XML::XPath;
use Data::Dumper;

my $eventxml = 'events.xml';
my $evenxp = XML::XPath->new(filename => $eventxml);
my $xpath = "//event/custom_attribute_list/custom_attribute[normalize-
+space(name)='SLB_SSRID']/value";

my @eventrecords = ();
foreach my $node ($evenxp->findnodes($xpath)) { 
  my $ssrid = $node->string_value;
  $ssrid =~ s/^\s+|\s+$//g ;
           push @eventrecords, 
      { eventid => $ssrid
      };
 
  } 
@eventrecords = sort{ $b->{eventid} <=> $a->{eventid} } @eventrecords;
+ #Sorting

 my $index;
 my @recordcount;
 for (@eventrecords) {
     $index++;
        push @recordcount, {
             line => $index
        };
    
 }
splice @eventrecords, $index, 0, @recordcount;
print Dumper \@eventrecords;
[download]

$VAR1 = [
    {
    'eventid' => 2667
    },
    {
    'eventid' => 2666
    },
    {
    'eventid' => 2656
    },
    {
    'line' => 1
    },
    {
    'line' => 2
    },
    {
    'line' => 3
      ];
[download]

expected code

$VAR1 = [
    {
    'eventid' => 2667
        'line' => 1
    },
    {
    'eventid' => 2666
        'line' => 2
    },
    {
    'eventid' => 2656
        'line' => 3
    },
    ];
[download]