indexfile' => {
                         'GCTCAGGA' => '4',
                         'AGCGTAGC' => '5',
                         'TTCTGCCT' => '3',
                         'CATGCCTA' => '6',
                         'TCGCCTTA' => '1',
                         'GTAGAGAG' => '7',
                         'GCGTAAGA' => '13',
                         'TAGATCGC' => '9',
                         'CTAGTACG' => '2',
                         'CTAAGCCT' => '16',
                         'CTCTCTAT' => '10',
                         'ACTGCATA' => '14',
                         'AGAGTAGA' => '12',
                         'TATCCTCT' => '11',
                         'AAGGAGTA' => '15',
                         'CCTCTCTG' => '8'
                       },
##</code><code>##

sub match_query(){
    my $indexfile = shift;
    my $queryseq     = shift;
    
    my @match_count;
    for my $key (keys %$indexfile){
        my $count;
        for(my $k=0; $k<length($key)-1; $k++){
            my $k_nuc = substr $key,$k,2;
            for(my $i=0; $i<length($queryseq)-1; $i++){
                my $i_nuc = substr $queryseq,$i,2;
                
                my $rel = $k-$i;
                if($k_nuc eq $i_nuc){
                    $count->{$rel} ||= 0;
                    $count->{$rel}  += 1;
                }else{
                    $count->{$rel} ||= 0;
                    $count->{$rel}  += 0;
                }
            }
        }
        
        my @array = sort{$b <=> $a} values %$count;
        my $max_count = shift @array;
        my $element;
        $element->{bar} = $key;
        $element->{max} = $max_count;
        push @match_count, $element;
    
    }
    my $result;
    @match_count = sort{$b ->{max} <=> $a->{max}} @match_count; #CODE #FAILS HERE DOESNT LIKE ->{max}
    if($match_count[0]->{max} == $match_count[1]->{max}){
        $result = 0;
    }elsif($match_count[0]->{max}>5){
      my $called_bar = $match_count[0]->{bar};
        $result = $indexfile->{$called_bar};
    }else{
       $result = 0;
    }
    return $result
    
}

##</code><code>##

Use of uninitialized value in numeric comparison (<=>) at /Users/XXXXXX/Desktop/test.pl line 602.