JavaScript实现对象数组与对象集合匹配并添加isExcluded属性

我有以下两个数据结构：

输入1：ticker排除状态数组 #

[
    {
        "ticker": "SPR",
        "isExcluded": false
    },
    {
        "ticker": "K",
        "isExcluded": false
    },
    {
        "ticker": "TR:CA",
        "isExcluded": false
    },
    {
        "ticker": "TEL:CA",
        "isExcluded": true
    }
]

输入2：ticker权重对象集合 #

{
    "K": {
        "ticker": "K",
        "weight": 19.15
    },
    "SPR": {
        "ticker": "SPR",
        "weight": 34.55
    },
    "TEL:CA": {
        "ticker": "TEL:CA",
        "weight": 30.61
    },
    "TR:CA": {
        "ticker": "TR:CA",
        "weight": 15.69
    }
}

我需要给第二个对象集合中的每个元素添加对应ticker的isExcluded属性，且该属性要放在weight之后，预期输出如下：

{
    "K": {
        "ticker": "K",
        "weight": 19.15,
        "isExcluded": false
    },
    "SPR": {
        "ticker": "SPR",
        "weight": 34.55,
        "isExcluded": false
    },
    "TEL:CA": {
        "ticker": "TEL:CA",
        "weight": 30.61,
        "isExcluded": true
    },
    "TR:CA": {
        "ticker": "TR:CA",
        "weight": 15.69,
        "isExcluded": false
    }
}

实现方案（以JavaScript为例） #

步骤1：构建ticker到isExcluded的映射表 #

先把第一个数组转换成以ticker为键、isExcluded为值的对象，这样可以快速查找对应状态，避免重复遍历数组：

const exclusionMap = inputArray.reduce((map, item) => {
    map[item.ticker] = item.isExcluded;
    return map;
}, {});

步骤2：遍历权重集合，添加isExcluded属性 #

遍历第二个对象集合的每个键，给每个对象追加isExcluded属性。为了保证属性顺序（weight之后紧跟isExcluded），可以通过解构原对象并重新构建新对象的方式实现：

const result = {};
for (const ticker in weightCollection) {
    const { weight } = weightCollection[ticker];
    result[ticker] = {
        ticker,
        weight,
        isExcluded: exclusionMap[ticker] ?? false // 兜底处理不存在的ticker，默认设为false
    };
}

完整代码示例 #

// 输入数据
const inputArray = [
    { "ticker": "SPR", "isExcluded": false },
    { "ticker": "K", "isExcluded": false },
    { "ticker": "TR:CA", "isExcluded": false },
    { "ticker": "TEL:CA", "isExcluded": true }
];

const weightCollection = {
    "K": { "ticker": "K", "weight": 19.15 },
    "SPR": { "ticker": "SPR", "weight": 34.55 },
    "TEL:CA": { "ticker": "TEL:CA", "weight": 30.61 },
    "TR:CA": { "ticker": "TR:CA", "weight": 15.69 }
};

// 构建映射表
const exclusionMap = inputArray.reduce((map, item) => {
    map[item.ticker] = item.isExcluded;
    return map;
}, {});

// 生成结果
const result = {};
for (const ticker in weightCollection) {
    const { weight } = weightCollection[ticker];
    result[ticker] = {
        ticker,
        weight,
        isExcluded: exclusionMap[ticker] ?? false
    };
}

console.log(JSON.stringify(result, null, 2));

内容的提问来源于stack exchange，提问作者Melanie Sigrid