Avoid for blindly declaring variables in perl :     my $scalarVar = ""; my $scalarVar = ''; my $scalarVar = (); my $scalarVar;

    my @arrayVar = ""; my @arrayVar = ''; my @arrayVar = (); my @arrayVar;

    my %hashVar = ""; my %hashVar = ''; my %hashVar = (); my $hashVar;

Please provide a sample and explanation about this to learn proper declaration of the variables. And it would be appreciate if someone can?

