Question

我一直在练习AngularJS1x做Lynda和Udemy的教程。我做了一个创建多项选择测验的教程。我想看看我是否通过重新创建它来理解代码，然后将其推得更远但是试图填充空白测验。

问题和答案全部来自JSON文件。填充检查正常工作，如果用户输入匹配JSON对象中的字符串，它可以正常工作。我没有做太多改变但是在尝试调用$ parent.index数组时代码不起作用。有关我用作多项选择测验的原始代码的参考，您可以找到该链接here

我很乐意，如果有人能够解释为什么我错了，如果我错误地设置它，那么我会变得更好。我将它与原始代码进行了比较，无法找到我出错的地方。

问题在于定位对象的数组编号。我还将展示下面的代码。

问题它位于调用qIndex参数的任何内容中，如下所示：

$scope.myQuestions[qIndex].questionState; //Says it is undefined

如果我给它一个像0这样的硬编码数组，那就可以了

$scope.myQuestions[0].questionState //If all of them are like this its fine as it calls the first question and finds the correct answer if typed into the input.

以下是代码：

HTML

    <div id="myQuiz" ng-controller="QuizController">
        <h1>Test Your Knowledge:<span>Saturn</span></h1>
        <div class="progress">  
            <div class="{{ ($index === activeQuestion) ? 'on' : 'off' }} 
                {{ (myQuestion.questionState === 'answered') ? 'answered' : 'unanswered' }}
                {{ (myQuestion.correctness === 'correct') ? 'correct' : 'incorrect' }}" 
                ng-repeat="myQuestion in myQuestions">
            </div>
        </div>


        <div class="intro {{ (activeQuestion > -1) ? 'inactive' : 'active' }}"> 
            <h2>Welcome</h2>
            <p>Click to begin to test your knowledge of Saturn.</p>
            <p class="btn" ng-click="activeQuestion = 0">Begin</p>
        </div>

        <div class="question
            {{ $index === activeQuestion ? 'active' : 'inactive' }}
            {{ myQuestion.questionState === 'answered' ? 'answered' : 'unanswered' }}" 
            ng-repeat="myQuestion in myQuestions">
            <p class="txt"> {{ myQuestion.instructions }} </p>
            <div class="txt" ng-bind-html="myQuestion.question | trustAsHtml">
            </div>  

            <p class="ans" 
                ng-class="{  
                    correct:isCorrect($parent.$index, $index)}"
                ng-click="checkAnswer($parent.$index, $index)">Check Answer 
            </p>


            <div class="feedback">
                <p ng-show="myQuestion.correctness === 'correct'"><strong>Correct</strong>.</p>
                <p ng-show="myQuestion.correctness === 'incorrect'">Oops! That is not correct.</p>

                <p> {{ myQuestion.feedback }} </p>

                <div class="btn" ng-click="selectContinue()">Continue</div>
            </div>

        <div class="results {{ (totalQuestions === activeQuestion) ? 'active' : 'inactive' }}">
            <div>
                <h3>Results</h3>

                <p>You Scored {{percentage}}% by correctly answering {{score}} of the total {{totalQuestions}} questions.</p>
                <p>Use the links below to challenge your friends.</p>

                <div class="share" ng-bind-html="createShareLinks(percentage)"></div>

            </div>
        </div>
    </div>

QUIZ.JS

(function(){
    var codeApp = angular.module('codeApp', ['ngSanitize']);

    codeApp.controller('QuizController', ['$scope', '$http', "$sce", function($scope, $http, $sce){
        $scope.score = 0;
        $scope.activeQuestion = -1;
        $scope.activeQuestionAnswered = 0;
        $scope.percentage = 0;

        $http.get('quiz_data.json').then(function(quizData){
            $scope.myQuestions = quizData.data;
            $scope.totalQuestions = $scope.myQuestions.length;
        });
        $scope.checkAnswer = function(qIndex,aIndex){
            var questionState = $scope.myQuestions[qIndex].questionState;

                if(questionState != 'answered') {

                    var userAnswer = $(".fillin").val();
                    console.log(aIndex); //logs 0
                    console.log(qIndex); //logs undefined

                    var correctAnswer = $scope.myQuestions[qIndex].questionAnswer;

                    $scope.myQuestions[qIndex].questionAnswer = correctAnswer;

                            if(userAnswer === correctAnswer){
                                $scope.myQuestions[qIndex].correctness = 'correct';
                                $scope.score += 1;
                                console.log('Correct!' + $scope.score);
                            }
                            else{
                                $scope.myQuestions[qIndex].correctness = 'incorrect';
                                console.log('Wrong!');
                            }
                        $scope.myQuestions[qIndex].questionState = 'answered';

                }else{
                    console.log('Something is wrong');
                }

                $scope.isCorrect = function(qIndex,aIndex){
                    return $scope.myQuestions[qIndex].questionAnswer === userAnswer;
                }
        }

        $scope.selectContinue = function(){
            return $scope.activeQuestion += 1;
        }

        $scope.createShareLinks = function(percentage){

            var url = 'http://codifydesign.com';
            var emailLink = '<input type="text" placeholder="hi" /><a class="btn email" href="mailto:?subject=Try to beat my quiz score!&amp;body=I scored a '+percentage+'% on this quiz about Saturn. Try to beat my score at '+url+'">Email a friend</a>';
            var twitterLink = '<a class="btn twitter" target="_blank" href="http://twitter.com/share?text=I scored a '+percentage+'% on this quiz about Saturn. Try to beat my score at&amp;hashtags=SaturnQuiz&amp;url='+url+'">Tweet your score</a>';
            var newMarkup = emailLink + twitterLink;
            return $sce.trustAsHtml(newMarkup);
        }
    }]).filter('trustAsHtml', [
    '$sce',
    function($sce) {
        return function(value) {
            return $sce.trustAsHtml(value);
        }
    }
    ]);
})();

JSON

[
    {
        "questionId": 0,
        "question" : "Saturn is <input id='guess-input' class='fillin' type='text' name='\"six\"'> many planets from the sun?",
        "questionAnswer" : "six"
    },
    {
        "questionId": 1,
        "question" : "Around Saturn are <input id='guess-input' class='fillin' type='text' name='\"rings\"'>",
        "questionAnswer" : "rings"
    }
]

Answer 1

在angularjs $parent.$index中，来自父作用域的$index。当你有嵌套循环时它很有用。然后，您可以使用$index构造从父作用域获取$parent.$index。您的代码没有嵌套循环。 ng-repeat="myQuestion in myQuestions"是最高级别的循环。因此它的父作用域中没有索引。我可以猜测，在原始代码中，另一个循环在另一个ng-repeat中有一个ng-repeat。

AngularJS中对象数组的函数参数未定义

1 个答案: