$arr = [null,12,'1','','','$','12',34,'65'];
$result = array_filter($arr,function($val){
return (is_numeric($val) and ($val > 0) and !empty($val) and !is_null($val));
});
$result = array_unique($arr,SORT_NUMERIC);
var_dump($result);
$result = array_unique($arr,SORT_NUMERIC);