#!/usr/bin/perl -w
use strict;
$|=1;              #turns off buffering for STDOUT

my @x = ( [1,'100'],
          [2,'106'],
          [3,'100A'],
          [4,'100B2'],
        );
        
foreach my $ref (@x)
{
   print "For $ref->[1] compareLT105 says: ", 
                        compareLT105($ref),"\n";
}
        
sub compareLT105
{
   my $arrayRef = shift;
   
   local $SIG{__WARN__} = 
      sub 
      {
          my $msg = shift;
          print STDERR $msg,"********";
          print STDERR "error array index: ",$arrayRef->[0]; 
          print STDERR " value is ",$arrayRef->[1], "\n";  
      };
  
   return 'true' if $arrayRef->[1] < 105;
   
   return 'false';
}

__END__
For 100 compareLT105 says: true
For 106 compareLT105 says: false
Argument "100A" isn't numeric in numeric lt (<) at C:\TEMP\warnexample.pl line 30.
********error array index: 3 value is 100A
For 100A compareLT105 says: true
Argument "100B2" isn't numeric in numeric lt (<) at C:\TEMP\warnexample.pl line 30.
********error array index: 4 value is 100B2
For 100B2 compareLT105 says: true