如何使用 Lodash 从带有对象数组的 object 中选择一个键？

Question

I want to filter an object for my server response data. My object Included with array of objects.

const object1 = {
    _id: '12345',
    publicId: 'object-1',
    arrayOfObject2: [
        {
            _id: '12345',
            publicId: 'object-2',
            username: 'allen',
            password: '123456',
        },
    ],
};

For example i want to pick publicId from object1 and username from each object2 .

i try this but this is not working:

const pickedObject = lodash.pick(object1, ['publicId', 'arrayOfObject2.username']);

Answer 1

You don't need Lodash for this.

const myObject = {
    ...object1,
    usernames: object1.arrayOfObject2.map(
        ({ username }) => username
    ),
};

Answer 2

To access the object properties, You can achieve that with the help of dot(.) notation. For ex: object.key

But If you want to access each object property value from an array of Objects. In this case you have to iterate it with the help of Array.map() method.

Live Demo :

 const object1 = { _id: '12345', publicId: 'object-1', arrayOfObject2: [ { _id: '12345', publicId: 'object-2', username: 'allen', password: '123456', }, ], }; const res = object1.arrayOfObject2.map(({ username }) => username); console.log(object1.publicId); // prints 'object-1' console.log(res); // prints ['allen']

Update: After looking into the author comment on another answer, Top level object also a part of array of objects. Hence, You can iterate that as well by using lodash ._map method.

Live Demo :

 const arr = [{ _id: '12345', publicId: 'object-1', arrayOfObject2: [ { _id: '12345', publicId: 'object-2', username: 'allen', password: '123456', } ] }]; const res = _.map(arr, (obj) => { return { publicId: obj.publicId, arrayOfObject2: _.map(obj.arrayOfObject2, (obj2) => { return { username: obj2.username } }) } }); console.log(res);

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