my $obj = bless {};

$obj->checkForm (...);
$obj->showPage (...);


sub checkForm {
    my ($self, @params) = @_;
    
    ...
    $self->addArrayXValue ($value);
    ...
}


sub showPage {
    my ($self, @params) = @_;
    my $value = $self->getArrayXValue (-1);
    ...
}


sub addArrayXValue {
    my ($self, $value) = @_;

    push @{$self->{arrayX}}, $value;
}


sub getArrayXValue {
    my ($self, $index) = @_;

    return $self->{arrayX}[$index];
}