#usr/bin/perl
 use Data::Dumper qw(Dumper);
foreach $x(@arr)
{
  I will do something and i will put something into an array called @val for each of the $x 
   $hash{$x}=[@val];
}
print Dumper \%hash;

foreach $y(@arr1)
{
  I will do something and i will put something into an array called @val2 for each of the $y
   $hash2{$x}=[@val2];
}
print Dumper \%hash2;

my %result;
foreach $key(keys %hash1)
{
 if(!exists $hash{$key})
  {
    $result{$a}=$hash1{$key};
    next;
  }
foreach $new(keys %$key)
 {
  $result{$key}{$new}=$hash{$key}{$new} if(!exists $hash{$key}{$new} && $hash1{$key}{$new}) eq $hash{$key}{$new});
 }
} 
print Dumper \%result;