如何使用lodash从Array中查找并返回一个对象？

Question

我的对象:

[
    {
        description: 'object1', id: 1
    },
    {
        description: 'object2', id: 2
    }
    {
        description: 'object3', id: 3
    }
    {
        description: 'object4', id: 4
    }
]

在我的函数中,我正在传递描述以找到匹配的ID:

function pluckSavedView(action, view) {
    console.log('action: ', action);
    console.log('pluckSavedView: ', view);  // view = 'object1'

    var savedViews = retrieveSavedViews();
    console.log('savedViews: ', savedViews);

    if (action === 'delete') {
        var delete_id = _.result(_.find(savedViews, function(description) {
            return description === view;
        }), 'id');

        console.log('delete_id: ', delete_id); // should be '1', but is undefined
    }
}

我正在尝试使用lodash的find方法:https://lodash.com/docs#find

但是我的变量delete_id未定义.

---

更新人们检查这个问题,Ramda是一个很好的库,可以做同样的事情lodash,但在一个更多功能的编程方式:) http://ramdajs.com/0.21.0/docs/

Answer 1

lodash和ES5

var song = _.find(songs, {id:id});

lodash和ES6

let song = _.find(songs, {id});

https://lodash.com/docs#find上的文档

Answer 2

传递给回调的参数是数组的元素之一.数组的元素是表单的对象{description: ..., id: ...}.

var delete_id = _.result(_.find(savedViews, function(obj) {
    return obj.description === view;
}), 'id');

您链接到的文档的另一个替代方案(lodash v3):

_.find(savedViews, 'description', view);

Lodash v4:

_.find(savedViews, ['description', view]);

Answer 3

你知道你可以轻松地做到这一点,不用find:

const savedViews = [{"description":"object1","id":1},{"description":"object2","id":2},{"description":"object3","id":3},{"description":"object4","id":4}];

const view = 'object2';

const delete_id = savedViews.find(obj => {
  return obj.description === view;
}).id;

console.log(delete_id);

DEMO

Answer 4

使用该find方法,您的回调将传递每个元素的值,如:

{
    description: 'object1', id: 1
}

因此,您需要以下代码:

_.find(savedViews, function(o) {
        return o.description === view;
})

Answer 5

您不需要Lodash或Ramda或任何其他额外的依赖项。

只需以功能性方式使用ES6 find（）函数：

savedViews.find(el => el.description === view)

有时，您需要使用3rd-party库来获取它们附带的所有好东西。但是，通常来说，在不需要依赖项时，请尝试避免它们。依赖项可以：

• your肿您捆绑的代码大小，
• 您将必须使它们保持最新状态，
• 他们可能会引入错误或安全风险

Answer 6

for this find the given Object in an Array, a basic usage example of _.find

const array = 
[
{
    description: 'object1', id: 1
},
{
    description: 'object2', id: 2
},
{
    description: 'object3', id: 3
},
{
    description: 'object4', id: 4
}
];

this would work well

q = _.find(array, {id:'4'}); // delete id

console.log(q); // {description: 'object4', id: 4}

_.find will help with returning an element in an array, rather than it’s index. So if you have an array of objects and you want to find a single object in the array by a certain key value pare _.find is the right tools for the job.

Answer 7

var delete_id = _(savedViews).where({ description : view }).get('0.id')

Answer 8

您可以使用以下内容

import { find } from 'lodash'

然后使用以下命令从列表中返回整个对象（不仅是其键或值）：

let match = find(savedViews, { 'ID': 'id to match'});

Answer 9

导入lodash使用

$ npm i --save lodash

var _ = require('lodash'); 

var objArrayList = 
    [
         { name: "user1"},
         { name: "user2"}, 
         { name: "user2"}
    ];

var Obj = _.find(objArrayList, { name: "user2" });

// Obj ==> { name: "user2"}