Passing list from Client side Controller to Server side Controller

Question

Is this the correct way of passing list from client side controller to server side controller. It's not working.

JavaScript Controller

    handleSaveQuestions: function(cmp, event, helper) {

    var action = cmp.get("c.saveQuestions");

    alert(cmp.get("v.QuestionList").length);//displays 12, which is correct

    action.setParams({ questionList : cmp.get("v.QuestionList") });
    action.setParams({ Questionnaire : cmp.get("v.Questionnaire") });

    action.setCallback(this, function(response) {

Apex Controller

    public static void saveQuestions(List<QuestionWrap> questionList, 
    Questionnaire__c Questionnaire){

    System.debug('questionList'+questionList.size());//displays 0, should have been 12

Answer 1

Problem is that I was setting action.setParams twice for two variables which seems to be wrong. Following change worked.

    action.setParams({ questionList : cmp.get("v.QuestionList"), Questionnaire : cmp.get("v.Questionnaire") });