http://www.perlmonks.org?node_id=1003866


in reply to runtime problem

Use :: instead of ->
if (my $numeral = Scalar::Util::looks_like_number($user_radius)) {

Scalar::Util does not have an object-oriented interface.

Similarly, you can also import the sub:

use Scalar::Util qw(looks_like_number); ... if (my $numeral = looks_like_number($user_radius)) {