Returns the alphabetic characters and digits of the parameter value.
@api
string $key The parameter key:
mixed $default The default value if the parameter key does not exist:
boolean $deep If true, a path like foo[bar] will find deeper items:
string The filtered value
public function getAlnum($key, $default = '', $deep = false) {
return preg_replace('/[^[:alnum:]]/', '', $this
->get($key, $default, $deep));
}