为什么我在控制台中收到一条错误消息，指出 getStoredQuests.push

Question

为什么我在控制台中收到getStoredQuests.push不是函数的错误消息Object.addQuestionOnLocalStorage

class Question{

    constructor(id, questionText, options, correctAnswer) {

        this.id = id;

        this.questionText = questionText;

        this.options = options;

        this.correctAnswer = correctAnswer;

    }

}

let questionLocalStorage = {

    setQuestionCollection: (newQuestion) => {

        localStorage.setItem('questionCollection', JSON.stringify(newQuestion));

    },

    getQuestionCollection: () => {

        return JSON.parse(localStorage.getItem('questionCollection'));

    },

    removeQuestionCollection: () => {

        localStorage.removeItem('questionCollection');

    }

}

newQuestion = new Question(questionId, newQuestText.value, optionsArr, corrAnswer);

getStoredQuests = questionLocalStorage.getQuestionCollection();

getStoredQuests.push(newQuestion);

questionLocalStorage.setQuestionCollection(getStoredQuests);

Answer 1

错误是因为getStoredQuests不是数组。您可能没有考虑过最初本地存储是否没有问题，然后localStorage.getItem('questionCollection')将返回空字符串，或者可能是您questionCollection在本地存储中有一些带有键的值，但格式不正确，无法解析为 JSON 数组对象。对于第一种情况，解决方案是检查是否localStorage.getItem('questionCollection')为空，然后从中返回空数组getQuestionCollection，对于第二种情况，您需要正确格式化数组“（将数组序列化以使用 JSON.stringify 存储）”。为了让你的问题正确理解，打开控制台看看是否有红线