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我正在尝试在 javascript 中进行测验，在其中我使用单选按钮检查提供给用户的答案。它检查第一个条目没问题，但是当它移动到第二个问题时，它会抛出一个未定义的类型错误cannot read property of undefined。在这条线上，我尝试过使用getElementById和使用 document.form，但无法弄清楚为什么会出现错误。该代码是第一个问题所用内容的复制和粘贴，效果很好！请帮忙！

var questionsChosen = new Array();
for (var i = 1;i<16 ;i++ )
{
    questionsChosen[i]= false;
}
function randomQuestion()
{
    var myQuestions = new Array();
    myQuestions[1] = "<tr><td><h4>Which one of these authors wrote and illustrated 'Calvin and Hobbes'?</h4></td></tr><tr><td><input type='radio' name='question1' value='Charles Schultz'>Charles Schultz<br><input type='radio' name='question1' id='correct' value='Bill Watterson'>Bill Watterson<br><input type='radio' name='question1' value='Jim Davis'>Jim Davis<br><input type='radio' name='question1' value='Tommy Peters'>Tommy Peters<br><hr/></td></tr>";

    myQuestions[2] = "<tr><td><h4>In the Calvin and Hobbes Comic, Who was Calvin's annoying neighbour?</h4></td></tr><tr><td><input type='radio' name='question2' id='correct' value='Susie Derkins'/>Susie Derkins<br><input type='radio' name='question2' value='Samantha Jones'/>Samantha Jones<br><input type='radio' name='question2' value='Sally Parker'/>Sally Parker<br><input type='radio' name='question2' value='Sarah Marsh'/>Sarah Marsh<br><hr/></td></tr>";

    for (var k = 1;k<myQuestions.length ;k++ )
    {
        document.write(myQuestions[k]);
        questionsChosen[i]= true;
    }
}

function checkAnswers()
{
    // use boolean to set whether a question has been asked or not. if it has then check here 
    // maybe something like if question1==true
    if (questionsChosen[1]= true)
    {
        var correctAnswer = document.myQuiz.question1[1].value;
        var userAnswer;
        for (i=0; i<document.myQuiz.question1.length; i++) 
        {
            if (document.myQuiz.question1[i].checked==true)
            {
                userAnswer =document.myQuiz.question1[i].value
            }
        }
        document.write("<br><br>Which one of these authors wrote and illustrated 'Calvin and Hobbes'?");
        document.write("<br>Your chosen answer is: "+userAnswer);
        if (correctAnswer == userAnswer)
        {
            document.write("<br>Correct!");
        }
        else document.write("<br>Incorrect... The answer was "+ correctAnswer);
    }


    if (questionsChosen[2]= true)
    {
        var correctAnswer = document.myQuiz.question2.value;
        var userAnswer;
        for (i=0; i<document.myQuiz.question2.length; i++) 
        {
            if (document.myQuiz.question2[i].checked==true)
            {
                userAnswer =document.myQuiz.question2[i].value
            }
        }
        document.write("<br><br>In the Calvin and Hobbes Comic, Who was Calvin's annoying neighbour?");
        document.write("<br>Your chosen answer is: "+userAnswer);
        if (correctAnswer == userAnswer)
        {
            document.write("<br>Correct!");
        }
        else document.write("<br>Incorrect... The answer was "+ correctAnswer);
    }
}

`

4

3 回答 3

0

If question2 is also an array like question1 you must state the index of the array whose value you would like to retrieve and set as the correct answer. question2 is the array itself. An array cannot have a value, but its elements have values. So it must read question2[1].value, or something like that.

于 2012-11-04T18:54:50.947 回答
0

我已经尝试了下面的代码，它工作得很好。 

<html><head></head><body>
    <script>
    var questionsChosen = new Array();
    for (var i = 1;i<16 ;i++ )
    {
        questionsChosen[i]= false;
    }
    function randomQuestion()
    {
        var myQuestions = new Array();
        myQuestions[1] = "<tr><td><h4>Which one of these authors wrote and illustrated 'Calvin and Hobbes'?</h4></td></tr><tr><td><input type='radio' name='question1' value='Charles Schultz'>Charles Schultz<br><input type='radio' name='question1' id='correct' value='Bill Watterson'>Bill Watterson<br><input type='radio' name='question1' value='Jim Davis'>Jim Davis<br><input type='radio' name='question1' value='Tommy Peters'>Tommy Peters<br><hr/></td></tr>";

        myQuestions[2] = "<tr><td><h4>In the Calvin and Hobbes Comic, Who was Calvin's annoying neighbour?</h4></td></tr><tr><td><input type='radio' name='question2' id='correct' value='Susie Derkins'/>Susie Derkins<br><input type='radio' name='question2' value='Samantha Jones'/>Samantha Jones<br><input type='radio' name='question2' value='Sally Parker'/>Sally Parker<br><input type='radio' name='question2' value='Sarah Marsh'/>Sarah Marsh<br><hr/></td></tr>";

        for (var k = 1;k<myQuestions.length ;k++ )
        {
            document.write(myQuestions[k]);
            questionsChosen[i]= true;
        }
        document.write("<a href='Javascript:void(0)' onclick='checkAnswers();'>Check Answers</a>");
    }

    function checkAnswers()
    {
        // use boolean to set whether a question has been asked or not. if it has then check here 
        // maybe something like if question1==true
        if (questionsChosen[1]= true)
        {
            var correctAnswer = document.myQuiz.question1[1].value;
            var userAnswer;
            for (i=0; i<document.myQuiz.question1.length; i++) 
            {
                if (document.myQuiz.question1[i].checked==true)
                {
                    userAnswer =document.myQuiz.question1[i].value
                }
            }
            document.write("<br><br>Which one of these authors wrote and illustrated 'Calvin and Hobbes'?");
            document.write("<br>Your chosen answer is: "+userAnswer);
            if (correctAnswer == userAnswer)
            {
                document.write("<br>Correct!");
            }
            else document.write("<br>Incorrect... The answer was "+ correctAnswer);
        }


        if (questionsChosen[2]= true)
        {
            var correctAnswer = document.myQuiz.question2[1].value;
            var userAnswer;
            for (i=0; i<document.myQuiz.question2.length; i++) 
            {
                if (document.myQuiz.question2[i].checked==true)
                {
                    userAnswer =document.myQuiz.question2[i].value
                }
            }
            document.write("<br><br>In the Calvin and Hobbes Comic, Who was Calvin's annoying neighbour?");
            document.write("<br>Your chosen answer is: "+userAnswer);
            if (correctAnswer == userAnswer)
            {
                document.write("<br>Correct!");
            }
            else document.write("<br>Incorrect... The answer was "+ correctAnswer);
        }
    }

    </script>
    <form name='myQuiz'>
        <script>
            randomQuestion();
        </script>

    </form>
    </body></html>
于 2012-11-05T05:16:29.017 回答
0

请将该行更改var correctAnswer = document.myQuiz.question2.value;为

var correctAnswer = document.myQuiz.question2[1].value;

放1,2,3,4水是正确答案

于 2012-11-04T18:56:47.353 回答