如何使用 Lodash 从两个不同的数组中获得相等的值答案

【问题标题】：How to get equal value from two different array using Lodash如何使用 Lodash 从两个不同的数组中获得相等的值
【发布时间】：2017-10-24 07:57:56
【问题描述】：

我在下面有两个 JSON 数组对象。我想获得匹配的 stdcontinfo JSON 值的标准名称并将其添加到 stdJson 相应的 JSON。

谁能帮我解决这个问题？

var stdJson = [{
        "_id": ObjectId("5923ed1f610be38692e88e4d"),
        "stdname": "Bala",
        "fathername": "Kannappan",
        "mark1": 78.0,
        "mark2": 70.0,
        "mark3": 98.0,
        "mark4": 88.0,
        "mark5": 100.0
    },
    {
        "_id": ObjectId("5923ed99610be38692e88e4e"),
        "stdname": "vetri",
        "fathername": "R",
        "mark1": 38.0,
        "mark2": 40.0,
        "mark3": 48.0,
        "mark4": 28.0,
        "mark5": 50.0
    },
    {
        "_id": ObjectId("5923edf6610be38692e88e4f"),
        "stdname": "kumba",
        "fathername": "K",
        "mark1": 68.0,
        "mark2": 60.0,
        "mark3": 68.0,
        "mark4": 88.0,
        "mark5": 35.0
    },
    {
        "_id": ObjectId("5923ee1a610be38692e88e50"),
        "stdname": "Jagadesh",
        "fathername": "P",
        "mark1": 100.0,
        "mark2": 90.0,
        "mark3": 89.0,
        "mark4": 100.0,
        "mark5": 95.0
    }, {
        "_id": ObjectId("5923ee6b610be38692e88e51"),
        "stdname": "Dayakar",
        "fathername": "R",
        "mark1": 70.0,
        "mark2": 80.0,
        "mark3": 69.0,
        "mark4": 60.0,
        "mark5": 55.0
    }
]

var stdcontinfo = [{
        "_id": ObjectId("592437891a87641edc58547e"),
        "stdname": "dev1",
        "email": "dev1@gmail.com",
        "phnum": 6545645645.0,
        "__v": 0
    },
    {
        "_id": ObjectId("5924ffe6837e5d2224f42e00"),
        "stdname": "Bala",
        "email": "Bala@gmail.com",
        "phnum": 9965148632.0,
        "__v": 0
    },
    {
        "_id": ObjectId("592500371e469423a4f65306"),
        "stdname": "kumba",
        "email": "kumba@gmail.com",
        "phnum": 9962651490.0,
        "__v": 0
    },
    {
        "_id": ObjectId("59250085f02d4c0face17820"),
        "stdname": "vetri",
        "email": "vetri@gmail.com",
        "phnum": 9962651490.0,
        "__v": 0
    },
    {
        "_id": ObjectId("592500c6c6a6af1d6c7c3fa5"),
        "stdname": "Jagadesh",
        "email": "Jagadesh@gmail.com",
        "phnum": 1234567890,
        "__v": 0
    }
]

【问题讨论】：

我的预期输出：var stdJson = [{ "stdname": "Bala", "fathername": "Kannappan", "mark1": 78.0, "mark2": 70.0, "mark3": 98.0 ，“mark4”：88.0，“mark5”：100.0，“email”：“Bala@gmail.com”，“phnum”：9965148632，}，{“stdname”：“vetri”，“fathername”：“R”， “mark1”：38.0，“mark2”：40.0，“mark3”：48.0，“mark4”：28.0，“mark5”：50.0，“email”：“vetri@gmail.com”，“phnum”：9962651490，}。 . . ]

标签： json node.js mongoose lodash

【解决方案1】：

通过 lodash，您可以使用其中一种相交函数。未经测试，但会是这样的：

var arrayOfSameObjects = _.intersectionBy(stdcontinfo, stdJson, 'stdname');

找到相同的对象后，您可以将其添加到stdJson：

var stdJson = stdJson.concat(arrayOfSameObjects);

参考资料：

https://lodash.com/docs/#intersectionBy

https://lodash.com/docs/#intersectionWith

【讨论】：

【解决方案2】：

我认为你在这里不需要 Lodash 只需使用简单的 JS：

stdJson.forEach(itemA=>{
    let resItem = stdcontinfo.find(itemB=>itemA.stdname === itemB.stdname);
    if(resItem){
        itemA.email = resItem.email;
        itemA.phnum = resItem.phnum;
    }
});

【讨论】：