lodash

问题 This question already has answers here : Understanding the fast alternative apply() in lodash (2 answers) Closed 11 months ago . The following code is the source code of negate function in lodash. As we can see that when the length of parameters less than 4, it uses switch-case instead of using apply directly. What magic about this code? Does it make the performance better? And why the split point is 4? function negate(predicate) { if (typeof predicate != 'function') { throw new TypeError

问题 I'm looking how to zip an array of objects with values including a new key for each value using lodash. Tried with zip, zipObject and map but I don't find the key. What I want to do is the following (avoiding to iterate manually over the arrays) var array = [ {a: 3, b: 42}, {c: 4}, {d: 12} ] var values = ['this', 'are', 'new', 'values'] var goal = [ {a: 3, b: 42, v: 'this'}, {c: 4, v: 'are'}, {d: 12, v:'new'} ] 回答1: You can use zipWith() to provide a custom iteratee: var newArray = _.zipWith

问题 I created template in index.html to generate html-code with js, code below. My Webpack configuration also below. When I run it with webpack-dev-server, I get error: title is not defined. Somehow webpack tries to resolve 'title' by self, instead of delegate it to 'lodash/template'. Please help me fix code, I'm in despair(. import path from 'path'; import glob from 'glob'; import webpack from 'webpack'; import ExtractTextPlugin from 'extract-text-webpack-plugin'; import HtmlWebpackPlugin from

问题 Using flat JavaScript or by making use of lodash, what is the simplest way (hoping lodash has a function) which I compare the following arrays and return the value which has changed: Before [ {id: 0, name: 'Bob', age: 27}, {id: 1, name: 'Frank', age: 32}, {id: 2, name: 'Joe', age: 38} ] After [ {id: 0, name: 'Bob', age: 27}, {id: 1, name: 'Frank', age: 33}, {id: 2, name: 'Joe', age: 38} ] So between before and after, Frank is now age 33, so how can I simply return: {id: 1, name: 'Frank', age:

问题 How do you convert a dotted keys into a javascript object and retain it's value? So I got this kind of response from an API and I need to parse it by key: value. { "property": "personal_info.address.city", "description": "Missing field" }, { "property": "personal_info.address.country", "description": "Missing field" }, So I achieved this: { 'personal_info.address.city': 'Missing field', 'personal_info.address.country': 'Missing field' } // by using this code (lodash) _.mapValues(_.keyBy(obj,

问题 In my application If data is undefined or null which is coming from service, my html will not load and I will get "data is undefined" error so I am tring to use lodash, but dont know how to use it.. In my below ts file this._PartService.GetDataValues().subscribe( result => { this.distributionData = this._PartService.part_data.partMasterDataCompleteList[0].partMasterData.plantSupplies.plantSupply } I will be getting "partMasterDataCompleteList" as undefiend or null if data is not there, so

问题 I have following object records : { "notes":[ { "id":1, "description":"hey", "userId":2, "replyToId":null, "postId":2, "parentId":null }, { "id":5, "description":"hey test", "userId":3, "replyToId":null, "postId":2, "parentId":null }, { "id":2, "description":"how are you", "userId":null, "replyToId":2, "postId":2, "parentId":null, "user":null } ] } I want to output it as: 2 object with id 1 object with id 2 (because replyToId value is same as userId 3 object with id 5 So basically I want to

问题 This question already has answers here : How to remove space in keys of a JSON object (3 answers) Closed 2 years ago . I have my json in the below format [{ "Id": "ALFKI", "Contact Name": "Maria Anders", "Contact Title": "Sales Representative", "City": "Berlin", "Slider": 10 }, { "Id": "ANATR", "Contact Name": "Ana Trujillo", "Contact Title": "Owner", "City": "México D.F.", "Slider": 5 }] My desired Json [{ "Id": "ALFKI", "ContactName": "Maria Anders", "ContactTitle": "Sales Representative",

问题 I got following data structure, which is an array of accounts objects, where some accounts are being parents to its children accounts, which in turn can be parents to other accounts etc.: [{ "id": "acc.1260446672222.11", "type": "EXPENSES_FOLDER", "name": "Expense Group", "balance": 3418.11, "children": [{ "id": "acc.1260446672238.27", "type": "EXPENSE", "name": "Advertising, Promotion and Entertainment Account", "balance": 0, "children": [] }, { "id": "acc.9a2492ba-0d82-4f4a-a1b4

问题 I was wondering if there is any difference in memory and performance between the 2 import. If I have lodash in my node module, does it compile all the file anyway no matter the import? 回答1: In theory, based on the specification for import, yes, there is supposed to be a difference. The specification allows for a compliant optimization to use static analysis of a named import in order to only load what is required to provide indexOf() , if the lodash module is written as an ES2015 module. It