帶有單選按鈕的JavaScript表單

我正在嘗試在JavaScript中進行測驗，其中我使用單選按鈕檢查提供給用戶的答案。它會檢查第一個條目，但是當它移動到第二個問題時，會拋出一個未定義的類型錯誤cannot read property of undefined。在這條線上，我試圖用getElementById和使用document.form搞亂，但一直未能找出錯誤原因。該代碼是複製和粘貼什麼用於第一個問題，它工作正常！請幫忙！帶有單選按鈕的JavaScript表單

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); 
    } 
}

來源

2012-11-04 springdo

這種情況發生在頁面解析後調用document.write（）時。它會自動調用'document.open（）'，它清除所有以前的JS和HTML。 – Teemu

那麼有沒有辦法讓我解決這個問題？我是否堅持寫文件直到所有的答案都產生了？ – springdo

只是再次通過它並更改document.write（）stmnts寫入所有更大的字符串。然後一次打印出來！謝謝您的幫助！ – springdo

如果問題2也好像問題1，您必須註明其價值要檢索並設置爲正確答案的數組的索引的數組。 question2是數組本身。數組不能有值，但其元素有值。所以它必須讀取question2 [1] .value或類似的東西。

來源

2012-11-04 18:54:50 Rob

你試過了，但它仍然返回相同的錯誤！ – springdo

請更改線路var correctAnswer = document.myQuiz.question2.value;到

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

把1,2,3,4 watever是正確答案

來源

2012-11-04 18:56:47

你好我有，但實際上覆制在錯誤的TXT。我正在嘗試一切工作。當我放回陣列位置時，它仍然會出現錯誤！ – springdo

我曾嘗試下面的代碼其工作完全正常。

<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>

來源

2012-11-05 05:16:29

帶有單選按鈕的JavaScript表單

回答

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