未捕獲的typeError未定義不是函數

Question

我調試了很多代碼，但是仍然遇到問題。 這是一次課堂作業，我問了我的教授，他也很震驚。 我確定修復此錯誤將對我的代碼有幫助，但是我不確定我出錯了。 你能幫忙嗎？ 這是錯誤

在此處輸入圖片說明

這是我的html代碼

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Magic Word - Sample</title>
    <script src="magicWord.js"></script>
</head>
<body>
    <div>
        <h2 align="center">WELCOME TO MAGIC WORD!</h2>
        <h3>Please enter your guess on the space below:</h3>
        <div>
            <input type="text" id="guestGuess" />
            <input type="submit" id="submitButton" onclick="javascript:enteredGuess();" />
        </div>
    </div>
    <div>
        <h3>Your guesses so far are: </h3>
        <div id="userGuesses"></div>
        <div>You have guessed: <span id="userAttempts"></span> times</div>
    </div>
</body>
</html>

這是我的Javascript

var numOfAttempts = 5;
var numOfGuesses = 0;
var magicWord = "Just";

function guessesUsed(attemptsTaken) {
    var numGuessesLeft = document.getElementById("userAttempts");
    numGuessesLeft.innerHTML = attemptsTaken;
}

//function guessesLeft(attemptsLeft) {
//  var numGuessesUsed = document.getElementById("guessesLeft");
//  numGuessesUsed.innerHTML = attemptsLeft;    
//}

function listWordsUsed(wordUsed) {
    var userTrials = document.getElementbyId("userGuesses").innerText;
    var divisor = document.createElement("div");
    divisor.innerHTML = "<div id=" + wordUsed + ">" + wordUsed + "</div>";
    userTrials.appendChild(divisor);
    return;
}

function enteredGuess() 
{
    //A user will enter a word and the word will be checked against the magic word
    //var enterGuess = prompt("What is your guess?", "Enter your guess here");
    var theGuess = document.getElementById("guestGuess");
    var magicWordResult;

    // Used lower case for both instances to compare both words
    if (theGuess.value.toLowerCase() == magicWord.toLowerCase()) 
    {
        //The user guesses the correct word
        magicWordResult = "Your guess was" + theGuess + "! Nice going!";
        //document.writeln("Your guess was: " + guestGuess + "\nand the magic word is " + magicWord);
    }
    else  //The user guesses wrong
    {
        //When user gets it wrong increase by one the numOfGuesses
        numOfGuesses ++;
        magicWordResult = "Your guess was" + theGuess + ". Nice try, but that's wrong, try again. \nYou have used " + numOfGuesses + " guesses.";

        // Subtract the amount of guesses from the amount of attempts
        var guessesLeft = numOfAttempts - numOfGuesses;

        if (numOfGuesses == numOfAttempts)
        {
            // When the user has reached all its attemps
            magicWordResult = "Sorry, you ran out of guesses. The magic word was " + magicWord + ".";
        }
        else
        {
            magicWordResult = "You still have " + guessesLeft + " guesses left.";
        }

        //To show the number of guesses the user has used
        guessesUsed(numOfGuesses);

        //To show the number of guesses the user has left
        //guessesLeft(guessesLeft);

        //Creates a list of the words used by the user
        listWordsUsed(theGuess);

    }

    // Display in an alert mode and show how the user is doing
    alert(magicWordResult);
}

我的錯誤在哪里？

Answer 1

這個：

var userTrials = document.getElementbyId("userGuesses").innerText;

以字符串形式獲取“ userGuesses”元素的文本，但是在這里：

userTrials.appendChild(divisor);

您的代碼將其視為DOM節點。 因為String實例上沒有“ appendChild”屬性，所以它是undefined ，並且可以解釋該錯誤-您正在嘗試進行函數調用，但函數引用卻是undefined 。

編輯 —哦，正如crclayton在評論中指出的那樣，“ getElementById（）”中的錯字也很重要。 我錯過了一個:)處理

未定義不是函數

錯誤是嘗試查找代碼可能undefined而不是引用函數的地方。 根據我的經驗，主要原因是：

錯字，就像“ getElementbyId”一樣。 如果函數名稱拼寫錯誤，JavaScript將無法理解，因此不會給出更好的錯誤。
關於變量或屬性指的是不滿意的假設，例如userTrials變量。
假設某個函數實際上返回了undefined （可能）返回了對該函數的引用

未捕獲的typeError未定義不是函數

問題描述

1 個解決方案

解決方案1
2 已采納 2014-08-16 19:19:03

未捕獲的typeError未定義不是函數

問題描述

1 個解決方案

解決方案1 2 已采納 2014-08-16 19:19:03

解決方案1
2 已采納 2014-08-16 19:19:03