Detect search criteria

In a search model I am doing

$search = Yii::$app->request->getQueryParam('PersonSearch');

Is there a simple way to know if the any of the search elements have criteria or not. Basically, I’m trying to detect if the are all empty, so none have a criteria.

Alternately, get a count of elements with a criteria

Alternately, list only the elements with a criteria

Right now I’m doing something like

$appliedSearchParams = false;
    foreach ($search as $key => $value) {
        if (strlen($value)>0){
            $appliedSearchParams = true;

Is there a method I’m unaware of that would be better than the above?