tie my %hash,'Tie::SortHash',{a=>1,b=>2};
delete $hash{'x'};
print join "\t",keys %hash;

##</code><code>##

Use of uninitialized value in splice at D:\Temp\tie_sorthash.pl line 43.
b

##</code><code>##

sub _ReOrder {
    my $self = shift;
    $self->[LOOKUP] = ();
    $self->[ARRAY] = ();

##</code><code>##

 defined $self->[ARRAY][$index] ? $self->[ARRAY][$index] : undef;