我的对象:
[
{
description: 'object1', id: 1
},
{
description: 'object2', id: 2
}
{
description: 'object3', id: 3
}
{
description: 'object4', id: 4
}
]
在下面的函数中,我传递了描述以找到匹配的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
是不确定的。
对于检查此问题的人员的更新,Ramda是一个不错的库,可以完成lodash的相同操作,但是以更实用的编程方式:)
http://ramdajs.com/0.21.0/docs/
传递给回调的参数是数组的元素之一。数组的元素是形式的对象{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种选择(lodash v3):
_.find(savedViews, 'description', view);
Lodash v4:
_.find(savedViews, ['description', view]);
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
您可以在香草JS中轻松完成此操作:
使用 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);
使用filter
(原始答案)
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.filter(function (el) {
return el.description === view;
})[0].id;
console.log(delete_id);
使用该find
方法,您的回调将被传递每个元素的值,例如:
{
description: 'object1', id: 1
}
因此,您需要如下代码:
_.find(savedViews, function(o) {
return o.description === view;
})
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,在不需要依赖时尽量避免依赖。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
为此,在数组中找到给定的对象,_.find的基本用法示例
const array =
[
{
description: 'object1', id: 1
},
{
description: 'object2', id: 2
},
{
description: 'object3', id: 3
},
{
description: 'object4', id: 4
}
];
这会很好
q = _.find(array, {id:'4'}); // delete id
console.log(q); // {description: 'object4', id: 4}
_.find有助于返回数组中的元素,而不是索引。因此,如果您有一个对象数组,并且希望通过某个键值对在数组中找到单个对象,则_.find是完成此任务的正确工具。
var delete_id = _(savedViews).where({ description : view }).get('0.id')
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'});
导入lodash
使用
$ npm i-保存lodash
var _ = require('lodash');
var objArrayList =
[
{ name: "user1"},
{ name: "user2"},
{ name: "user2"}
];
var Obj = _.find(objArrayList, { name: "user2" });
// Obj ==> { name: "user2"}
根据名称获取ID
{
"roles": [
{
"id": 1,
"name": "admin",
},
{
"id": 3,
"name": "manager",
}
]
}
fetchIdBasingOnRole() {
const self = this;
if (this.employee.roles) {
var roleid = _.result(
_.find(this.getRoles, function(obj) {
return obj.name === self.employee.roles;
}),
"id"
);
}
return roleid;
},
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文章标签:arrays , javascript , lodash
版权声明:本文为原创文章,版权归 javascript 所有,欢迎分享本文,转载请保留出处!
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