基于父级值在嵌套数组中添加新键值对

我有一个包含问题的数组，每个问题对象里有可选选项列表和正确答案字符串。我需要给每个选项对象添加一个correct_answer字段，用true/false标记该选项是否为正确答案。尝试使用.map()和.forEach()方法，但不知道如何在处理选项时访问对应的正确答案值。

原数据 #

const data = [
    {
        "question": "数学常数e的近似值是多少？",
        "options": [
            {
                "option": "1.41",
            },
            {
                "option": "1.62",
            },
            {
                "option": "2.72",
            },
            {
                "option": "3.14",
            }
        ],
        "correct_answer": "2.72"
    },
    {
        "question": "动画《一拳超人》的主角叫什么名字？",
        "options": [
            {
                "option": "杰诺斯",
            },
            {
                "option": "KING",
            },
            {
                "option": "埼玉",
            },
            {
                "option": "索尼克",
            }
        ],
        "correct_answer": "埼玉"
    }
]

期望结果 #

const data = [
    {
        "question": "数学常数e的近似值是多少？",
        "options": [
            {
                "option": "1.41",
                "correct_answer": false,
            },
            {
                "option": "1.62",
                "correct_answer": false,
            },
            {
                "option": "2.72",
                "correct_answer": true,
            },
            {
                "option": "3.14",
                "correct_answer": false,
            }
        ],
        "correct_answer": "2.72"
    },
    {
        "question": "动画《一拳超人》的主角叫什么名字？",
        "options": [
            {
                "option": "杰诺斯",
                "correct_answer": false,
            },
            {
                "option": "KING",
                "correct_answer": false,
            },
            {
                "option": "埼玉",
                "correct_answer": true,
            },
            {
                "option": "索尼克",
                "correct_answer": false,
            }
        ],
        "correct_answer": "埼玉"
    }
]

解决方案 #

方法1：使用.forEach()修改原数组 #

.forEach()会直接遍历并修改原数组元素，适合不需要保留原数据的场景：

data.forEach(question => {
    const correctAnswer = question.correct_answer;
    question.options.forEach(option => {
        option.correct_answer = option.option === correctAnswer;
    });
});

方法2：使用.map()返回新数组 #

如果需要保留原数组不变，用.map()生成新数组，所有对象均为浅拷贝后的新实例：

const newData = data.map(question => ({
    ...question,
    options: question.options.map(option => ({
        ...option,
        correct_answer: option.option === question.correct_answer
    }))
}));

核心逻辑说明 #

遍历每个问题时，直接访问当前问题的correct_answer属性，再遍历该问题的options数组，将每个选项的option值与正确答案做全等比较，把结果赋值给新添加的correct_answer字段即可。

内容的提问来源于stack exchange，提问作者Nivel