javascript - 未捕获的类型错误 : Cannot read property 'quest' of undefined

Question

我知道这个问题之前可能已经被问过，但我相信这个很棒的社区可以原谅我:) 我正在开发(测验时间)应用程序，但有一个错误正在杀死我:( 当我每次运行此应用程序并按下锁定按钮时，它会按预期运行，但在随机单击次数(可能是 4 或 2)后，它会停止并给出此错误:

         Uncaught TypeError: Cannot read property 'quest' of undefined
at QuestionReset 

这是代码

        $(document).ready(function () {
var overwallScore = 0;
//prototype
function Question(quest, option1, option2, option3, correct) {
    this.quest = quest;
    this.option1 = option1;
    this.option2 = option2;
    this.option3 = option3;
    this.correct = correct;

}
//creating questions
var question1 = new Question("1 + 1", 2, 3, 3, 1);
var question2 = new Question("2 + 2", 4, 3, 3, 2);
var question3 = new Question("3 + 3", 6, 3, 3, 3);
var question4 = new Question("4 + 4", 8, 3, 3, 1);
var question5 = new Question("5 + 5", 10, 3, 3, 2);
var question6 = new Question("6 + 6", 12, 3, 3, 3);
//the questions array
var questions = [];
//pushing questions to array
questions.push(question1);
questions.push(question2);
questions.push(question3);
questions.push(question4);
questions.push(question5);
questions.push(question6);
var randomQuestionIndex = Math.floor(Math.random() * 6 + 1);

function QuestionPre() {
    randomQuestionIndex = Math.floor(Math.random() * 6 + 1);
    document.querySelector("#question").innerHTML = questions[randomQuestionIndex].quest;
    document.querySelector(".option-1").innerHTML = questions[randomQuestionIndex].option1;
    document.querySelector(".option-2").innerHTML = questions[randomQuestionIndex].option2;
    document.querySelector(".option-3").innerHTML = questions[randomQuestionIndex].option3;

}
QuestionPre();

function QuestionReset() {
    randomQuestionIndex = Math.floor(Math.random() * 6 + 1);
    document.querySelector("#question").innerHTML = questions[randomQuestionIndex].quest;
    document.querySelector(".option-1").innerHTML = questions[randomQuestionIndex].option1;
    document.querySelector(".option-2").innerHTML = questions[randomQuestionIndex].option2;
    document.querySelector(".option-3").innerHTML = questions[randomQuestionIndex].option3;
}
document.querySelector(".lock-btn").addEventListener("click", function () {
    if (document.querySelector(".option-" + questions[randomQuestionIndex].correct + "-check").checked === true) {
        alert("Correct, such a Genius !");
        overwallScore = overwallScore + 1;
        QuestionReset();
    } else {
        alert("Wrong mate, such a bad luck !");
        randomQuestionIndex = Math.floor(Math.random() * 6 + 1);
        QuestionReset();


    }
}); });

提前致谢。

Answer 1

问题出在线路上

var randomQuestionIndex = Math.floor(Math.random() * 6 + 1);

randomQuestionIndex 的值可能超出范围。只需删除 +1 部分即可。