我一直从Json中得到随机的未定义值

希望有人能帮我解决这个问题-可能是我忽略的一些简单的事情。

我一直得到未定义的值随机-正确的值有时出现，有时我得到"未定义"。

我已经尝试将var q1;更改为var q1 = '';等，虽然这停止了未定义的值，但我会得到一个随机的空白值。

任何想法?提前感谢:)

  $(document).ready(function() {
    var questionNumber = 0;
    var questionBank = new Array();
    var stage = "#game1";
    var stage2 = new Object;
    var questionLock = false;
    var numberOfQuestions;
    var score = 0;
    $.getJSON('activity.json', function(data) {
        for (i = 0; i < data.quizlist.length; i++) {
          questionBank[i] = new Array;
          questionBank[i][0] = data.quizlist[i].question;
          questionBank[i][1] = data.quizlist[i].option1;
          questionBank[i][2] = data.quizlist[i].option2;
          questionBank[i][3] = data.quizlist[i].option3;
          questionBank[i][4] = data.quizlist[i].option4;
        }
        numberOfQuestions = questionBank.length;
        displayQuestion();
      }) //gtjson
    function displayQuestion() {
        var rnd = Math.random() * 4;
        rnd = Math.ceil(rnd);
        var q1;
        var q2;
        var q3;
        var q4;
        if (rnd == 1) {
          q1 = questionBank[questionNumber][1];
          q2 = questionBank[questionNumber][2];
          q3 = questionBank[questionNumber][3];
          q4 = questionBank[questionNumber][4];
        }
        if (rnd == 2) {
          q2 = questionBank[questionNumber][1];
          q3 = questionBank[questionNumber][2];
          q4 = questionBank[questionNumber][3];
          q1 = questionBank[questionNumber][4];
        }
        if (rnd == 3) {
          q3 = questionBank[questionNumber][1];
          q4 = questionBank[questionNumber][2];
          q1 = questionBank[questionNumber][3];
          q3 = questionBank[questionNumber][4];
        }
        if (rnd == 4) {
          q4 = questionBank[questionNumber][1];
          q1 = questionBank[questionNumber][2];
          q2 = questionBank[questionNumber][3];
          q3 = questionBank[questionNumber][4];
        }
        $(stage).append('<div class="questionText">' + questionBank[questionNumber][0] + '</div><div id="1" class="option">' + q1 + '</div><div id="2" class="option">' + q2 + '</div><div id="3" class="option">' + q3 + '</div><div id="4" class="option">' + q4 + '</div>');
        $('.option').click(function() {
          if (questionLock == false) {
            questionLock = true;
            //correct answer
            if (this.id == rnd) {
              $(stage).append('<div class="feedback1">CORRECT</div>');
              score++;
            }
            //wrong answer  
            if (this.id != rnd) {
              $(stage).append('<div class="feedback2">INCORRECT</div>');
            }
            setTimeout(function() {
              changeQuestion()
            }, 1000);
          }
        })
      } //display question
    function changeQuestion() {
        questionNumber++;
        if (stage == "#game1") {
          stage2 = "#game1";
          stage = "#game2";
        } else {
          stage2 = "#game2";
          stage = "#game1";
        }
        if (questionNumber < numberOfQuestions) {
          displayQuestion();
        } else {
          displayFinalSlide();
        }
        $(stage2).animate({
          "right": "+=800px"
        }, "slow", function() {
          $(stage2).css('right', '-800px');
          $(stage2).empty();
        });
        $(stage).animate({
          "right": "+=800px"
        }, "slow", function() {
          questionLock = false;
        });
      } //change question
    function displayFinalSlide() {
        $(stage).append('<div class="questionText">You have finished the quiz!<br><br>Total questions: ' + numberOfQuestions + '<br>Correct answers: ' + score + '</div>');
      } //display final slide

  }); //doc ready

  {"quizlist":[
    {
    "question":"1. Sam wants to be sure to listen carefully to what the influencee says during an important conversation. What are the correct steps to listen effectively?",
        "option1":"Ask questions, listen to the answers, and acknowledge what is said.",
        "option2":"Listen for feelings and facts, clarify, and share a personal point of view.",
        "option3":"Share a personal point of view, clarify, and ask for feedback.",
        "option4":"Use closed questions to get the facts, clarify, and confirm what is said."
    },
    {
    "question":"2. A team member tried to convince colleagues that the best course of action to increase team performance was to ask for volunteer coaches to train newer team members. The team member presented plans for the coaching program on three different occasions, but was not able to persuade any colleagues to support the plan. Now, the team member wants to learn more about how others on the team recommend improving performance. What approach will have the most impact to understand how others view the situation?",
    "option1":"Meet with the colleagues as a group and ask them to discuss their point of view about the problem and the proposed solution.",
    "option2":"Explain that he/she has given up on their ideas and will go along with anything the group is willing to do.",
    "option3":"Meet with colleagues as a group and paint a picture of the future if the problem is not addressed immediately.",
    "option4":"Suggest that colleagues send their comments and ideas directly to the team member. "
    },
    {
    "question":"3. A supervisor explained the reasons for a new procedure and started a discussion with the team. The supervisor said, “I expect you to adopt the new procedure immediately and don’t want us to waste time. If you do this in the next two weeks, I will be able to tell the leadership team that we have met our objective ahead of schedule. If you don’t do this, there could be problems.” Which influencing style did this supervisor use? ",
        "option1":"Dominating. The supervisor is pushing the team by putting pressure on the team.",
        "option2":"Asserting. The supervisor is describing what she/he wants and pushing the team by explaining his/her reasoning for the proposal.",
        "option3":"Storytelling. The supervisor is pulling the team together by presenting a picture of the common elements.",
        "option4":"Responding. The supervisor is pulling team members toward the idea by explaining is thinking."
    }    
]
}